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PDF file - 391K, Figure S5. Knockdown of β-catenin abrogates the ability of AR79 to increase nuclear B-catenin expression in DU145 and C4-2B cell lines

PDF file - 290K, Figure S2. AR79 has no impact on p-HIPK2 expression in prostate cancer cell lines.

PDF file - 56K, DNA profiling of LNCaP, C4-2B and DU145

PDF file - 66K, Figure S1. Mouse body weights were not impacted by AR79 treatment.

PDF file - 200K, Figure S4. AR79 increases the cell number of Du145luc cells in the presence or absence of ST-2 co-culture.

Due to its bone anabolic activity, methods to increase Wnt activity, such as inhibitors of dickkopf-1 and sclerostin, are being clinically explored. Glycogen synthase kinase (GSK3β) inhibits Wnt signaling by inducing β-catenin degradation, and a GSK3β inhibitor, AR79, is being evaluated as an osteoanabolic agent. However, Wnt activation has the potential to promote tumor growth; therefore, the goal of this study was to determine if AR79 has an impact on the progression of prostate cancer. Prostate cancer tumors were established in subcutaneous and bone sites of mice followed by AR79 administration, and tumor growth, β-catenin activation, proliferation, and apoptosis were assessed. Additionally, prostate cancer and osteoblast cell lines were treated with AR79, and β-catenin status, proliferation (with β-catenin knockdown in some cases), and proportion of ALDH+CD133+ stem-like cells were determined. AR79 promoted prostate cancer tumor growth, decreased phospho-β-catenin, increased total and nuclear β-catenin, and increased tumor-induced bone remodeling. Additionally, AR79 treatment decreased caspase-3 and increased Ki67 expression in tumors and increased bone formation in normal mouse tibiae. Similarly, AR79 inhibited β-catenin phosphorylation, increased nuclear β-catenin accumulation in prostate cancer and osteoblast cell lines, and increased proliferation of prostate cancer cells in vitro through β-catenin. Furthermore, AR79 increased the ALDH+CD133+ cancer stem cell–like proportion of the prostate cancer cell lines. In conclusion, AR79, while being bone anabolic, promotes prostate cancer cell growth through Wnt pathway activation.Implications: These data suggest that clinical application of pharmaceuticals that promote Wnt pathway activation should be used with caution as they may enhance tumor growth. Mol Cancer Res; 11(12); 1597–610. ©2013 AACR.

PDF file - 294K, Figure S3. AR79 increases bone formation in normal mouse tibiae.

PDF file - 56K

Synthetic phosphatidylinositol phosphate (PtdInsPn) derivatives play a pivotal role in broadening our understanding of PtdInsPn metabolism. However, the development of such tools is reliant on efficient enantioselective and regioselective synthetic strategies. Here we report the development of a divergent synthetic route applicable to the synthesis of deuterated PtdIns4P and PtdIns5P derivatives. The synthetic strategy developed involves a key enzymatic desymmetrisation step using Lipozyme TL-IM®. In addition, we optimised the large-scale synthesis of deuterated myo-inositol, allowing for the preparation of a series of saturated and unsaturated deuterated PtdIns4P and PtdIns5P derivatives. Experiments in MCF7 cells demonstrated that these deuterated probes enable quantification of the corresponding endogenous phospholipids in a cellular setting. Overall, these deuterated probes will be powerful tools to help improve our understanding of the role played by PtdInsPn in physiology and disease.

Cachexia and muscle wasting are very common among patients suffering from cancer, chronic obstructive pulmonary disease, and other chronic diseases. Ghrelin stimulates growth hormone secretion via the ghrelin receptor, which subsequently leads to increase of IGF-1 plasma levels. The activation of the GH/IGF-1 axis leads to an increase of muscle mass and functional capacity. Ghrelin further acts on inflammation, appetite, and adipogenesis and for this reason was considered an important target to address catabolic conditions. We report the synthesis and properties of an indane based series of ghrelin receptor full agonists; they have been shown to generate a sustained increase of IGF-1 levels in dog and have been thoroughly investigated with respect to their functional activity.

A new model for translational research and drug repositioning has recently been established based on three-way partnerships between public funders, the pharmaceutical industry and academic investigators. Through two pioneering initiatives - one involving the Medical Research Council in the United Kingdom and one involving the National Center for Advancing Translational Sciences of the National Institutes of Health in the United States - new investigations of highly characterized investigational compounds have been funded and are leading to the exploration of known mechanisms in new disease areas. This model has been extended beyond these first two initiatives. Here, we discuss the progress to date and the unique requirements and challenges for this model.

BACKGROUND Targeting kinases as regulators of cellular processes that drive cancer progression is a promising approach to improve patient outcome in GBM management. The glycogen synthase kinase 3 (GSK-3) plays a role in cancer progression and is known for its pro-proliferative activity in gliomas. The anti-proliferative and cytotoxic effects of the GSK-3 inhibitor AZD2858 were assessed in relevant in vitro and in vivo glioma models to confirm GSK-3 as a suitable target for improved single agent or combination treatments. MATERIAL AND METHODS The immortalised cell line U251 and the patient derived cell lines GBM1 and GBM4 were used in in vitro studies including MTT, clonogenic survival, live cell imaging, immunofluorescence microscopy and flow cytometry to assess the cytotoxic and anti-proliferative effects of AZD2858. Observed anti-proliferative effects were investigated by microarray technology for the identification of target genes with known roles in cell proliferation. Clinical relevance of targeting GSK-3 with the inhibitor either for single agent or combination treatment strategies was determined by subcutaneous and orthotopic in vivo modelling. Whole mount mass spectroscopy was used to confirm drug penetration in orthotopic tumour models. RESULTS AZD2858 was cytotoxic at low micromolar concentrations and at sub-micromolar concentrations (0.01 - 1.0 μM) induced mitotic defects in all cell lines examined. Prolonged mitosis, centrosome disruption/duplication and cytokinetic failure leading to cell death featured prominently among the cell lines concomitant with an observed S-phase arrest. No cytotoxic or anti-proliferative effect was observed in normal human astrocytes. Analysis of the RNA microarray screen of AZD2858 treated glioma cells revealed the dysregulation of mitosis-associated genes including ASPM and PRC1, encoding proteins with known roles in cytokinesis. The anti-proliferative and cytotoxic effect of AZD2858 was also confirmed in both subcutaneous and orthotopic in vivo models. In addition, combination treatment with AZD2858 enhanced clinically relevant radiation doses leading to reduced tumour volume and improved survival in orthotopic in vivo models. CONCLUSION GSK-3 inhibition with the small molecule inhibitor AZD2858 led to cell death in glioma stem cells preventing normal centrosome function and promoting mitotic failure. Normal human astrocytes were not affected by treatment with the inhibitor at submicromolar concentrations. Drug penetration was observed alongside an enhanced effect of clinical radiotherapy doses in vivo. The reported aberrant centrosomal duplication may be a direct consequence of failed cytokinesis suggesting a role of GSK-3 in regulation of mitosis in glioma. GSK-3 is a promising target for combination treatment with radiation in GBM management and plays a role in mitosis-associated events in glioma biology.

Mammalian target of rapamycin (mTOR) is essential in controlling several cellular functions. This pathway is dysregulated in keloid disease (KD). KD is a common fibroproliferative dermal lesion with an ill-defined treatment strategy. KD demonstrates excessive matrix deposition, angiogenesis, and inflammatory cell infiltration. In KD, both total and phosphorylated forms of mTOR and p70(S6K)(Thr421/Ser424) are upregulated. Therefore, the aim of this study was to investigate adenosine triphosphate-competitive inhibitors of mTOR kinase previously unreported in keloid and their comparative efficacy with Rapamycin. Here, we present two mTOR kinase inhibitors, KU-0063794 and KU-0068650, that target both mTORC1 and mTORC2 signaling. Treatment with either KU-0063794 or KU-0068650 resulted in complete suppression of Akt, mTORC1, and mTORC2, and inhibition of keloid cell spreading, proliferation, migration, and invasive properties at a very low concentration (2.5 μmol l(-1)). Both KU-0063794 and KU-0068650 significantly (P0.05) inhibited cell cycle regulation and HIF1-α expression compared with that achieved with Rapamycin alone. In addition, both compounds induced shrinkage and growth arrest in KD, associated with the inhibition of angiogenesis, induction of apoptosis, and reduction in keloid phenotype-associated markers. In contrast, Rapamycin induced minimal antitumor activity. In conclusion, potent dual mTORC1 and mTORC2 inhibitors display therapeutic potential for the treatment of KD.

Homochiral (E)- and (Z)-enamides derived from SuperQuat (S)-4-phenyl-5,5-dimethyl-oxazolidin-2-one undergo highly diastereoselective epoxidation upon treatment with dimethyldioxirane. Subsequent epoxide opening with meta-chlorobenzoic acid proceeds via a stereoselective SN1-type process, with retention of configuration, to give the corresponding 1′-m-chlorobenzoyl-2′-hydroxy derivatives. Treatment of the SuperQuat enamides with mCPBA effects this two-step transformation in one pot. Reductive cleavage of the isolated 1′-m-chlorobenzoyl-2′-hydroxy derivatives (≥96% de) generates homochiral 1,2-diols in ≥96% ee. Alternatively, regioselective lithiation of the enamide at C(1′) with tBuLi followed by reaction with an aromatic aldehyde and in situ O-benzylation generates a 1′-(benzyloxy-aryl-methyl) substituted enamide with high diastereoselectivity. Subsequent oxidative cleavage of the enamide C{double bond, long}C bond with NaIO4/RuCl3 followed by methanolysis of the resultant N-acyl fragment furnishes an O-benzyl protected α-hydroxy methyl ester in high ee. © 2008 Elsevier Ltd. All rights reserved.

(R)-4-Phenyl-5,5-dimethyl-oxazolidin-2-one, readily available from d -phenylglycine, is shown to be an effective chiral auxiliary for stereoselective conjugate additions to attached α,β-unsaturated N-acyl moieties. Its utility is demonstrated by the asymmetric synthesis of the antifungal, antibacterial (−)-Aplysillamide B.

N -acyl-5,5-dimethyl-oxazolidin-2-ones can function as versatile latent aldehyde equivalents - reductive cleavage with DIBAL-H affords aldehydes in good yield, while tandem DIBAL-H/Wittig methodology affords α,β-unsaturated esters.

An efficient, easy to perform, one-pot reaction cascade for the synthesis of 2,5-disubstituted pyrroles from p-toluenesulfonyl protected imines and 4-nitrobut-1-yne under a combination of base and gold(III) catalysis is reported.

The synthesis of a series of chiral auxiliaries, 5-substituted-3,3-dimethyl-2-pyrrolidinones, “quats”, from L-glutamic acid is described. Efficient regeneration of the chiral auxiliaries from their N-pivaloyl derivatives is readily achieved with LiOH in THF-water at 20°C.

The highly enantioselective preparation of synthetically useful tetrahydropyridine derivatives employing a one-pot nitro-Mannich/hydroamination cascade is reported. This approach utilizes an asymmetric organocatalytic nitro-Mannich reaction followed by a gold-catalyzed alkyne hydroamination/isomerization sequence that yields the desired tetrahydropyridines in good yields and high diastereo- and enantioselectivities.

2,4-Disubstituted-5-fluoropyrimidine is a biologically active molecular core seen in various anticancer agents such as 5-fluorouracil (5-FU). As part of a programme aimed at discovering kinase inhibitors, routes to two series of novel compounds (5-fluoropyrimidine-2-carboxamides and 5-fluoropyrimidine-4-carboxamides) were successfully executed. For the first series, regioselective substitution at the 4-position of the pyrimidine with an amine (HNR 1 R 2 ) was achieved, followed by preparation of the amide at the 2-position. The route to the second series involved introduction of the methoxy protecting group at the 4-position, which allowed subsequent amine substitution to occur at the 2-position. The 4-amide substituent was finally introduced by direct conversion of the 4-methoxy into a 4-chloro group followed by transformation into an amide by palladium catalysis.

Novel indole-3-thio-, 3-sulfonyl- and 3-oxy-aryl-1-acetic acids are reported which are potent, selective antagonists of the chemoattractant receptor-homologous expressed on Th2 lymphocytes receptor (CRTh2 or DP2). Optimization required maintenance of high CRTh2 potency whilst achieving a concomitant reduction in rates of metabolism, removal of cyp p450 inhibition and minimization of aldose reductase and aldehyde reductase activity. High quality compounds suitable for in vivo studies are highlighted, culminating in the discovery of AZD1981 (22).

A novel series of small molecule C5a antagonists is reported. In particular, in vitro metabolic studies and solution based combinatorial synthesis are demonstrated as useful tools for the rapid identification of antagonists with low in vitro clearance. Members of this series specifically inhibited the binding of (125)I-labeled C5a to human recombinant C5a receptor (C5aR). In functional cell assays these compounds displayed surmountable antagonism against C5a and did not demonstrate any detectable agonist activity.

Fragment-based lead generation (FBLG) has recently emerged as an alternative to traditional high throughput screening (HTS) to identify initial chemistry starting points for drug discovery programs. In comparison to HTS screening libraries, the screening sets for FBLG tend to contain orders of magnitude fewer compounds, and the compounds themselves are less structurally complex and have lower molecular weight. This report summarises the advent of FBLG within the industry and then describes the FBLG experience at AstraZeneca. We discuss (1) optimising the design of screening libraries, (2) hit detection methodologies, (3) evaluation of hit quality and use of ligand efficiency calculations, and (4) approaches to evolve fragment-based, low complexity hits towards drug-like leads. Furthermore, we exemplify our use of FBLG with case studies in the following drug discovery areas: antibacterial enzyme targets, GPCRs (melanocortin 4 receptor modulators), prostaglandin D2 synthase inhibitors, phosphatase inhibitors (protein tyrosine phosphotase 1B), and protease inhibitors (b-secretase).

Starting with the weak agonist indomethacin, a series of potent, selective CRTh2 (DP(2)) antagonists have been discovered as potential treatments for asthma, allergic rhinitis and other inflammatory diseases.

The synthesis and utility of the 3,3-dimethyl-5-substituted-2-pyrrolidinone 'Quat' chiral auxiliary in stereoselective enolate reactions of attached N-acyl side chains combined with the mild and non-racemising conditions required for the ultimate removal of the chiral side chain is described. © 2002 Elsevier Science Ltd. All rights reserved.

A lead generation and optimization program delivered the highly selective and potent CatC inhibitor 10 as an in vivo tool compound and potential development candidate. Structural studies were undertaken to generate SAR understanding.

The highly enantioselective preparation of trisubstituted pyrrolidine derivatives employing a one-pot nitro-Mannich/hydroamination cascade is reported. This cascade approach utilizes an asymmetric bifunctional organocatalytic nitro-Mannich reaction followed by a gold-catalyzed allene hydroamination reaction. The products are afforded in good yields and excellent diastereo- and enantioselectivities.

Reduction of α-substituted-(S)-N-acyl-4-benzyl-5,5-dimethyl-oxazolidin-2-ones with DIBAL-H in CH2Cl2 affords α-substituted aldehydes with no loss of stereochemical integrity at their α-centre. Copyright (C) 2000 Elsevier Science Ltd.

A random library of phage displayed peptides was screened for binding to a biotinylated derivative of paclitaxel (Taxol). Affinity-selected peptides were analyzed for similarity to human proteins. There was no significant similarity between the paclitaxel-selected peptides and tubulin. However, a subset of the peptides was identified that exhibits significant similarity to a non-conserved region of the anti-apoptotic human protein Bcl-2: ELISA assays confirmed binding of paclitaxel to Bcl-2, and circular dichroism spectroscopy demonstrated that a substantial conformational change accompanies this binding. In vivo, treatment with paclitaxel has been shown to lead to Bcl-2 inactivation with concomitant phosphorylation of residues in a disordered, regulatory loop region of the protein. Similarity between paclitaxel-selected peptides and this loop region implicate these residues in drug binding, and suggest that the apoptotic action of paclitaxel may involve the binding of paclitaxel to Bcl-2. These results demonstrate that peptides displayed on the surface of bacteriophage particles can mimic the ligand-binding properties of disordered regions of proteins.

Due to its bone anabolic activity, methods to increase Wnt activity, such as inhibitors of dickkopf-1 and sclerostin, are being clinically explored. Glycogen synthase kinase (GSK3β) inhibits Wnt signaling by inducing β-catenin degradation, and a GSK3β inhibitor, AR79, is being evaluated as an osteoanabolic agent. However, Wnt activation has the potential to promote tumor growth; therefore, the goal of this study was to determine if AR79 has an impact on the progression of prostate cancer. Prostate cancer tumors were established in subcutaneous and bone sites of mice followed by AR79 administration, and tumor growth, β-catenin activation, proliferation, and apoptosis were assessed. Additionally, prostate cancer and osteoblast cell lines were treated with AR79, and β-catenin status, proliferation (with β-catenin knockdown in some cases), and proportion of ALDH+CD133+ stem-like cells were determined. AR79 promoted prostate cancer tumor growth, decreased phospho-β-catenin, increased total and nuclear β-catenin, and increased tumor-induced bone remodeling. Additionally, AR79 treatment decreased caspase-3 and increased Ki67 expression in tumors and increased bone formation in normal mouse tibiae. Similarly, AR79 inhibited β-catenin phosphorylation, increased nuclear β-catenin accumulation in prostate cancer and osteoblast cell lines, and increased proliferation of prostate cancer cells in vitro through β-catenin. Furthermore, AR79 increased the ALDH+CD133+ cancer stem cell–like proportion of the prostate cancer cell lines. In conclusion, AR79, while being bone anabolic, promotes prostate cancer cell growth through Wnt pathway activation. Implications: These data suggest that clinical application of pharmaceuticals that promote Wnt pathway activation should be used with caution as they may enhance tumor growth. Mol Cancer Res; 11(12); 1597–610. ©2013 AACR.

A diastereoselective one-pot nitro-Mannich/hydroamination cascade to substituted pyrrolidines bearing three stereocenters is developed.

Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging.GSK-3 inhibitors caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28days exposure in rats. After 7days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH1–34 or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT.GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption.

An efficient one-pot nitro-Mannich/hydroamination cascade reaction for the synthesis of substituted pyrrolidines bearing three stereocentres is reported. Proceeding under the control of a combination of base and gold(I) catalysts, the cascade reaction affords the pyrrolidine products in high yields with good to excellent diastereoselectivities.

The procedure allows a new approach to optically active tetrahydropyridines which can be converted into several derivatives such as the piperidine (IV).

4-(Methyl, phenyl, benzyl, and i -propyl)-5,5-dimethyl-oxazolidin-2-ones, readily available from α-amino acids, are shown to be effective chiral auxiliaries for stereoselective enolate alkylations and conjugate additions of attached N-acyl moieties.

A series of dual CCR3/H1 antagonists based on a bispiperidine scaffold were discovered. Introduction of an acidic group overcame hERG liability. Bioavailability was optimised by modulation of physico-chemical properties and physical form to deliver a compound suitable for clinical evaluation.

Enolates derived from the N -propionoyl derivative of the “quat” chiral auxiliary ( R )-(−)-5-methyl-3,3-dimethyl-2-pyrrolidinone undergo highly stereoselective aldol and alkylation reactions. Removal of the auxiliary has been demonstrated with LiOH, PhCH 2 OLi, MeOMgBr and LiAlH 4 to generate respectively (2 R ,3 R )-3-hydroxy-2-methyl-3-phenylpropionic acid in homochiral form, and with 96% e.e. ( S )-2-methyl-3-phenylpropionic acid and derived methyl and benzyl esters and with >94% e.e. ( S )-2-methyl-3-phenylpropanol.

An efficient method for the preparation of substituted pyrroles (IV) from sulfonyl imines (I) and nitrobutyne (II) is presented.

The synthesis of a series of chiral auxiliaries, 5-substituted-3,3-dimethyl-2-pyrrolidinones, “quats”, from L-glutamic acid is described. Efficient regeneration of the chiral auxiliaries from their N-pivaloyl derivatives is readily achieved with LiOH in THF-water at 20°C.

Enolates derived from the N -propionoyl derivative of the “quat” chiral auxiliary ( R )-(−)-5-methyl-3,3-dimethyl-2-pyrrolidinone undergo highly stereoselective aldol and alkylation reactions. Removal of the auxiliary has been demonstrated with LiOH, PhCH 2 OLi, MeOMgBr and LiAlH 4 to generate respectively (2 R ,3 R )-3-hydroxy-2-methyl-3-phenylpropionic acid in homochiral form, and with 96% e.e. ( S )-2-methyl-3-phenylpropionic acid and derived methyl and benzyl esters and with >94% e.e. ( S )-2-methyl-3-phenylpropanol.

4-(Methyl, phenyl, benzyl, and i -propyl)-5,5-dimethyl-oxazolidin-2-ones, readily available from α-amino acids, are shown to be effective chiral auxiliaries for stereoselective enolate alkylations and conjugate additions of attached N-acyl moieties.

(R)-4-Phenyl-5,5-dimethyl-oxazolidin-2-one, readily available from d -phenylglycine, is shown to be an effective chiral auxiliary for stereoselective conjugate additions to attached α,β-unsaturated N-acyl moieties. Its utility is demonstrated by the asymmetric synthesis of the antifungal, antibacterial (−)-Aplysillamide B.

Studies on the alkylation of enolates derived from a range of N-acyl-5,5-dimethyloxazolidin-2-ones and N-acyl-5,5-diphenyloxazolidin-2-ones reveal that high yields and high diastereoselectivities are best obtained when homochiral 4-isopropyl-5,5-dimethyloxazolidin-2-one is employed as a chiral auxiliary.

N -acyl-5,5-dimethyl-oxazolidin-2-ones can function as versatile latent aldehyde equivalents - reductive cleavage with DIBAL-H affords aldehydes in good yield, while tandem DIBAL-H/Wittig methodology affords α,β-unsaturated esters.

The proclivity of alpha-branched N-2'-benzyl-3'-phenylpropionyl derivatives of (S)-4-benzyl-5,5-dimethyl-, (S)-4-phenyl-5,5-dimethyl-, (S)-4-isopropyl-5,5-dimethyl-, (S)-4-benzyl- and (S)-4-benzyl-5,5-diphenyl-oxazolidin-2-ones to generate directly 2-benzyl-3-phenylpropionaldehyde upon hydride reduction with DIBAL is investigated. The (S)-4-benzyl-5,5-dimethyl-derivative proved optimal for inhibition of endocyclic nucleophilic attack, giving 2-benzyl-3-phenylpropionaldehyde in good yield upon reduction. Application of this methodology for the asymmetric synthesis of chiral aldehydes via diastereoselective enolate alkylation of a range of (S)-N-acyl-4-benzyl-5,5-dimethyloxazolidin-2-ones to afford and array of alpha-substituted-N-acyl-5,5-dimethyloxazolidin- 2-ones (85-94% de) and subsequent reduction with DIBAL afforded directly non-racemic alpha-substituted aldehydes without loss of stereochemical integrity (87-94% ee). The extension of this protocol for the asymmetric synthesis of beta-substituted aldehydes is demonstrated, via the diastereoselective conjugate addition of a range of organocuprates to (S)-N-acyl-4-phenyl-5,5-dimethyloxazolidin-2-ones which proceeds with high diastereoselectivity (generally > 95% de). Reduction of the conjugate addition products with DIBAL gives non-racemic beta-substituted aldehydes in high yields and in high ee (generally > 95% ee). This methodology is exemplified by the asymmetric synthesis of (R)-3-isopropenylhept-6-enal, which has previously been used in the synthesis of (3Z,6R)-3-methyl-6-isopropenyl-3,9-decadien-1-yl acetate, a component of the sex pheromones of the California red scale.

Homochiral (E)-enamides derived from (S)-4-phenyl-5,5-dimethyl-oxazolidin-2-one undergo highly diastereoselective epoxidation upon treatment with dimethyldioxirane (DMDO). Treatment with m-chloroperbenzoic acid (MCPBA) produces syn-(4S, 1′R,2′)-1′ -acyloxy-2′-hydroxy derivatives with high diastereoselectivity, consistent with a mechanism involving initial epoxidation and subsequent in situ S N1 type epoxide opening and trapping with m-chlorobenzoic acid. Reductive cleavage of the isolated 1′-acyloxy-2′-hydroxy derivatives generates 1,2-diols in high yields and in high ee.

A study of the properties of N-hydrocinnamoyl- derivatives of 5,5-dimethyloxazolidin-2-one, 4,4-dimethyloxazolidin-2-one and oxazolidin-2-one upon hydride reduction with DIBAL-H demonstrates that the 5,5-dimethyl-group is essential for inhibition of endocyclic nucleophilic attack. For instance, treatment of N-hydrocinnamoyl-5,5-dimethyloxazolidin-2-one with DIBAL-H results in the selective formation of the stable N-1'-hydroxyalkyl derivative which may be regarded as a masked hydrocinnamaldehyde equivalent, as treatment under basic conditions affords the parent aldehyde in excellent yield. Treatment of N-hydrocinnamoyl-4,4-dimethyloxazolidin-2-one with DIBAL-H under identical conditions affords a complex mixture of products, including the formate ester product of endocyclic cleavage. As an alternate strategy, DIBAL-H reduction of straight chain and branched N-acyl-5,5-dimethyloxazolidin-2-one derivatives, followed by a Horner-Wadsworth-Emmons reaction affords alpha,beta-unsaturated esters in good yields. Branching alpha- to the exocyclic carbonyl in N-acyl-oxazolidinones inhibits DIBAL-H reduction, but this can be overcome by precomplexation with ZnCl2, with subsequent fragmentation generating either the corresponding aldehyde or alpha,beta-unsaturated esters. The addition of ZnCl2 has been shown to increase the diastereoselectivity observed in Wadsworth-Horner-Emmons reactions of lithiated phosphonates.

Reduction of α-substituted-(S)-N-acyl-4-benzyl-5,5-dimethyl-oxazolidin-2-ones with DIBAL-H in CH2Cl2 affords α-substituted aldehydes with no loss of stereochemical integrity at their α-centre.

An efficient and simple synthesis of oxazolidin-2-one SuperQuat chiral auxiliaries is described which provides rapid access to multigram quantities of the auxiliaries.