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Homogeneous polyimide (PI)/silica nanohybrid films were prepared using acetoxy group functionalized PI and silsesquiazane (SSQZ) as a silica precursor. During the heat treatment at 250 °C in a nitrogen atmosphere, the SSQZ was converted to silica. At the same time, the acetoxy groups of PI were converted into hydroxyl groups and formed covalent bonds with silica to make the resulting hybrid film homogeneous. FE-SEM and AFM analysis showed no evidence of macro-phase separation. As a result, the hybrid films exhibited improved thermal and mechanical properties, including 5% weight loss temperature, residual amount at 1,000 °C, coefficient of thermal expansion, and pencil hardness. The optical properties of the films also improved with showing a similar optical transmittance and lower yellow index.

The opening of the epoxide bridge in N-substituted 2,3,7,7a-tetrahydro-3a,6-epoxyisoindol-1-ones by the action of BF3⋅Et2O in acetic anhydride at 25°C over 1 h proceeds through an SN1 mechanism. The allylic type cation formed in the first step is stabilized by the addition of an acetoxy group at C-5 in the isoindole system to give a mixture of cis and trans isomers of 5,6-diacetoxy-2,3,5,6,7,7a-hexa-hydroisoindol-1-ones, which are aromatized under these conditions over 24 h to give 2,3-dihydro-1H-isoindol-1-ones.

Replacement of the acetoxy group in 3-methylbenzoylaminomethyl acetate with N- and S-nucleophiles generated from amines and thio compounds using sodium hydride gives the corresponding N-aminomethyl- and N-thiomethylbenzamides.

A series of 2-aryl-3-(4,5,6-trimethylpyrimidin-2-yl) thiazolidin-4-ones (1a–1c) and their derivatives bearing a lipophilic substituent, like acetoxy group (3a–3c), propionyloxy group (4a–4c), methyl (5d and 5e) at C-5 on thiazolidin-4-one ring were designed, synthesized and evaluated for their HIV-RT inhibitory activity. Using selfcatalyzed Pummerer reaction, compounds 3a–3c and 4a–4c were obtained in good yield (63.1%–75.2%). Preliminary anti-HIV-RT test of these derivatives indicated that compounds 1a–1c, 4b (propionyloxy group at C-5) showed moderate HIV-RT inhibitory activity and compounds 5d and 5e with methyl at C-5 showed a weak HIVRT inhibitory activity. Structure activity relationship analysis suggested that the substituted groups on C-5 would be unfavorable to anti-HIV-RT activity and that the steric effect might play a critical role in the anti-HIV RT activity.

By use of 2D-QSAR and CoMFA approaches, a series of scalarane derivatives were assessed for which structural features confer antitubercular activity. The major contributions deduced from the 2D-QSAR models suggested positive effects on antitubercular activity of the shadow area on the XZ plane (representing the steric descriptor), the dipole moment, and relative positive charge (both representing the electrostatic descriptor). The contour map from the CoMFA model indicated the requirement for oxygenated functionality surrounding the furan moiety, particularly the extension of the acetoxy group either on C-16 toward the β plane or on C-19 toward the α plane. On the other hand, the region crowning C-12 was considered a sterically and negative-electrostatically disfavored area. Therefore, extension of a bulky negative functional group toward this area would diminish the binding interaction. The 2D-QSAR results agreed well with those from the CoMFA model and suggested the structural features of polarizable functionality that would enhance the antitubercular activity of the compounds in this series.

The dehydration products of driman-8α,11-diol-11-monoacetate that are formed upon reaction with several dehydrating agents and the products from elimination of the C-8 acetoxy group in driman-8α,11-diol diacetate were investigated in detail. A new effective synthesis of drimenylacetate from driman-8α, 11-diol-11-monoacetate by its regioselective dehydration using methanesulfonic acid trimethylsilyl ether was developed.

The 11 β-H epimer of Azadirachtin-I, isolated from the seed kernels of Azadirachta indica A. Juss (Neem), was characterized by both NMR and X-ray crystallographic techniques. NMR data reveals that the H11 proton is in β-orientation and the X-ray studies confirm this observation. The compound crystallized in space group P21 with the cell parameters a = 11.933(2) A, b = 7.752(5) A, c = 17.241(9) A, β = 106.80(3)○. Though the structural features are similar to the 11 β-H epimer of Azadirachtin-H, the orientation of the acetoxy group at C3 is different. The dihedral angle C9–C8–C14–O13, which describes the relative orientation of the modified decalin and modified furan moities of the molecule, is 23.3(8)○.

The addition of the phthalimidonitrene fragment, resulting from oxidation ofN-aminophthalimide by lead tetraacetate at −20 to −30°C, to the N=N-bond of 5-bromospirol[l-pyrazolinio-3,1′-cyclopropane] (1) affords, apart from the stable 5-bromo-N {spiro[l-pyrazolinio-3,1′-cyclopropane]}-N-phthalimidoamide (azimine2), regioisomeric azimine3, which is completely transformed into 3-acetoxy-N-{spiro[l-pyrazolinio-5,1′-cyclopropane]}-N-phthalimidoamide (4) under the reaction conditions. The acetoxy group in this product easily undergoes nuclcophilic substitution on treatment with McOH, NaN3, or the starting bromopyrazoline1. The structures of azimines obtained were established using NMR spectra, and the structure of the product of reaction of4 with1 was additionally proved by X-ray difraction data.

A series of 7α-methoxy-2-[(substituted)methylene]cephem sulfones was synthesized. The compounds with an acetoxy group at the C-3′ position as a leaving group were found to be potent inhibitors of HLE. Selected compounds are also found to be antithrombin agents.

The reactions of [(2-acetoxyetoxy)methyl]dimethylchlorosilane and 1-acetoxy-2-(dimethylchlorosilylmethoxy)benzene with the cage phenylcopper and phenylmanganese siloxanes leads to the cleavage of the M—O—Si bond to give metal chlorides and six-unit cyclosiloxanes with an acetoxy group in the organic substituent at the silicon atom. Methanolysis of these acetoxy derivatives does not affect the ring structure and affords the corresponding polyhydric alcohols.

Heating of (1S,3S)-3-acetoxymethyl-1-(2-acetoxyvinyl)-2,2-dimethylcyclopropane with bromoform under phase-transfer catalysis affords dibromocyclopropane viaaddition of dibromocarbene to the double bond. In an analogous reaction with chloroform, the trichloromethyl anion adds to the double bond in the α-position with respect to the acetoxy group.

The structure of the new iridoid glycoside velpetin isolated from the herbNepeta velutina has been established on the basis of spectral characteristics and chemical transformations as 1,5,8,9-tetraepiixoroside.

The reactions of 1,4-dioxa-2-silacyclohexanes with acetyl chloride lead to the cleavage of the Si−O bond to form chlorotriorganosilanes containing the acetoxy group in the organic radical at the silicon atom. Hydrolysis of these chlorosilanes affords bis(acetoxy-alkoxy(aryloxy)methyl)disiloxanes, while the reactions with cage copper sodium phenylsiloxane give dodecaphenyl[dodeca(acetoxyorganodimethylsilyloxy)]cyclododecasiloxanes.

An x-ray structural investigation has been made of pennogenin diacetate (diffractometer, direct method, anisotropic refinement, R factor 0.050). The spatial structure of the molecule has been established. The acetylation of the hydroxy group in position 17α in pennogenin is connected with the steric hindrance arising between the atoms of the acetoxy group and the atoms of ring D.

1. A new reaction was discovered for the nucleophilic substitution of the acetoxy group in acylals by the trichloromethyl group under Makosza cyclopropanation conditions. 2. A general method was developed for the synthesis of 1-trichloromethyl-2-alken(or alkan)-1-ol acetates.

The nitration of 5-chloromethylsalicylaldehyde leads to 3-nitro-5-chloromethylsalicylaldehyde, the chlorine atom in which is smoothly replaced by a hydroxy or acetoxy group. The salicylaldehydes obtained condense with 1,3,3-trimethyl-2-methylene-indoline to give the corresponding photochromic indolinespirochromenes. The spectral-kinetics of the photochromic transformations of the spirochromenes are discussed.

1-Methyl-2-cyanoindoles react with aromatic aldehydes in acidic media to give 1-methyl-2-cyano-3-(α-halobenzyl)indoles. Replacement of the halogen by a cyano group gives (indolyl)-phenylacetonttrile, reduction of which gives the corresponding tryptamine. An attempt to replace the acetoxy group in 1-methyl-2-carbomethoxy-3-(α-acetoxybenzyl)indole by a cyano group was accompanied by rearrangement to give 1-methyl-2-cyano-3-benzylindole.

The nitrosation of 2,4,6-trimethylpyrimidine 1,3-dioxide and the bromination of 2,4,6-trimethyl- and 2-ethyl-4,6-dimethylpyrimidine 1,3-dioxides take place primarily at the methyl groups in the 4 and 6 positions of the heteroring. In the reaction of 2,4,6-trimethylpyrimidine 1,3-dioxide with phosphorus oxychloride chlorine is incorporated in the methyl group in the 2 position of the heteroring, while in the reaction with acetic anhydride an acetoxy group is incorporated in the methyl group in the 2 position and in the 5 position of the heteroring, whereas in the case of tosyl chloride a tosyloxy group is incorporated in the 5 position of the heteroring.

The introduction of an acetoxy group into the pyrrol nucleus with lead tetraacetate is described and therewith involved mechanistic aspects are discussed. According to this method we obtained the aldehyde13 required for the synthesis of 3-methoxypyrromethene16.

Treatment of 2,4,8,10-tetranitro-6(5H)-phenanthridinone with hexamethylphosphoric triamide leads to intermolecular nucleophilic substitution of the nitro group by a hydroxy group, the source of which is the water contained in the solvent, to give 10-hydroxy-2,4,8-trinitro-6(5H)-phenanthridinone. An intramolecular interaction with the participation of a proton of the aromatic ring and an oxygen atom of the hydroxy or acetoxy group of the 10-hydroxy- or 10-acetoxy-2,4,8,-trinitro-6(5H)-phenanthridinone, the properties of which are characteristic for an intramolecular hydrogen bond, was detected by x-ray diffraction analysis and PMR spectroscopy.

The leaves ofAjuga turkestanica (Rg1.) Briq. have yielded a new ecdysone — 22-acetyl-cyasterone. The mass spectrum of this new ecdysone and the features of it due to the presence of the acetoxy group at C-22 have been discussed.

In the reduction of mestranol acetate with metals in liquid ammonia, as well as the reduction of ring A and the splitting out of the acetoxy group, the addition of hydrogen to C17 takes place and the main products are the 17-vinyl and 17-ethyl derivatives (III) and (VII), respectively. Under conditions favoring the saponification of the acetate, the reduction product is the 17-ethylidene derivative (VIII).

1. We have developed a method for the preparation of chloromethylphosphine oxides by substitution of the acetoxy group in acetoxymethylphosphine oxides by chlorine using gaseous HC1 at 180–200°C. 2. We have prepared methylbis(chloromethyl)phosphine oxide by reaction of gaseous HC1 with tris(acetoxymethyl)phosphine or tetrakis(hydroxymethyl)phosphonium chloride. In the same way we synthesized dimethylchloromethylphosphine oxide from tris(hydroxymethyl)phosphine methylsulfate.

1. The molecular weight of the compound studied is determined by the most intense ion peak with maximum m/e value which, as a rule, is the ion peak, with m/e (M - 60)+.. 2. The ratios of the peaks for the molecular ion and (M-AcOH) ion of esters of 24-nor- and 21,24-dinorchola-5,16,20 (22)-trienic acids (IV)–(VI) depends on the stereochemistry at the Δ20(22) bond. 3. The presence of ion peaks with m/e 213 and 226 is characteristic for compounds containing hydroxyl and/or acetoxy groups at C-16 and C-17.

1. The 1-ethyl-3-aeetoxypropyl and 1-ethyl-4-acetoxybutyl radicals were respectively generated by the oxidative decarboxylation of the 2-ethyl-3-acetoxybutanoic and 2-ethyl-4-acetoxypentanoic acids under the influence of lead tetraacetate, and a study was made of their oxidation by the acetate, trifluoroacetate, fluoborate, sulfate, chloride and perchlorate of divalent copper. 2. Most of the copper salts oxidize the 1-ethyl-3-acetoxypropyl and 1-ethyl-4-acetoxybutyl radicals exclusively to the 2- and 3-pentenyl and the 3- and 4-hexenyl acetates, with the predominant formation of the isomers where the acetoxy group is furthest away from the double bond. Ligands that are coordinated with the copper are practically without effect on the ratio of the formed isomeric alkenyl acetates.

1. In an investigation of the IR spectra of a number of mono- and bis-cyclopentadienyltitanium acylates, monodentate coordination of the acyl ligand in these compounds was established. 2. For cyclopentadienyltitanium triacetate, an intermolecular interaction on account of the formation of bridge bonds, accomplished by part of the acetoxy groups of the molecule, was detected.

1. The condensation of 1-(1-ace toxyvinyl)cyclohexene (I) with maleic anhydride was studied: it results in an 80% yield of the anti-cis anhydride (III), which is quantitatively hydrolyzed by water to anti-cis-4-acetoxy 1,2,3,5,6,7,8,8a-octahydro-1,2-naphthalenedicarboxylic acid (IV), which gives the anti-cis acetoxy diester (V) with diazomethane. 2. By hydrolysis of the acetoxy group in the acid (IV) and the diester (V) we prepared the traps-anti-cis keto acid (VI) and the traps-anti-traps keto diester (X), and Clemmensen reduction of these gave the previously described traps-anti-cis decahydro-1,2-naphthalenedicarboxylic acid (IX) and the traps-anti-traps-decahydro 1,2-naphthalenedicarboxylic diester (XI), thus confirming the configurations of these last compounds. 3. The steric transformations of some monoesters of this series were studied, and it was shown that they readily undergo isomerization at the 2-alkoxycarbonyl group.

1. A study was made of the hydrolysis of cis- and trans-1-acetyl-1,2-cyclohexanediol diacetates in alkaline and acid conditions. The hydrolysis of the 1,2-diacetates probably pass through the intermediate formation of tertiary monoacetates with subsequent intramolecular migration of acetyl and finally hydrolysis of the secondary monoacetates formed into the corresponding diols. 2. In the hydrolysis of the trans-diol diacetate (II) under acid conditions, as well as the trans monoacetate (V) and the trans-diol (VI), a compound of unestablished structure is formed; this is close in Rf value to the trans acetate (V), and when it is kept it is gradually converted into (V). 3. The acetolysis of trans-1-acetyl-1-bromo-2-cyclohexanol acetate, which was prepared for the first time, probably goes via the formation of an intermediate cyclic orthoacetate and is accompanied by the removal of the bromine atom with inversion of configuration by a mechanism of intramolecular SN2 substitution.

1. A study was made of the reactions of hypobromous acid with cis- and trans-1-ethynyl-2-methylcyclohexanols, 2-propyn-1-ol and its acetate, 2-butyne-l,4-diol and its diacetate, and l,4-dichloro-2-butyne. 2. In all these cases the course of the reaction of hypobromous acid with the triple bond was anomalous and led to the formation of the corresponding unsaturated dibromo compounds, which were probably of trans configuration. Some of these products were prepared also by bromination of the original acetylenic compounds with bromine in nonpolar solvents in the light. 3. A hypothesis is advanced concerning the effect of a neighboring hydroxy or acetoxy group on the character of the reaction of hypobromous acid with the triple bond. 4. In the bromination of 1-ethynylcyclohexanol acetate with bromine in aqueous methanol normal addition of hypobromous acid to the triple bond occurs and the known 1- (2,2-dibromoacetyl) cyclohexanol acetate is isolated in 65% yield.

1. The condensation of butadienyl acetate with maleic anhydride proceeds sterically selectively with formation of the cis-cis adduct (II), the configuration of which was proved by hydrogenation and lactonization. 2. In the condensation of butadienyl acetate with dimethyl fumarate both possible isomeric trans-trans and trans-cls adducts (XIV) and (XV) were isolated, and their configurations were proved by a study of their catalytic hydrogenation and hydrolysis and by an examination of molecular models. 3. Derivatives of the cis-cis and trans-cis series having an axial arrangement of the acetoxy group were found to be of low stability, and on catalytic hydrogenation, alkaline hydrolysis, and heating they lose acetic acid with formation of various cyclohexene-l,2-dicarboxylic acids. The isomeric compounds of the trans-transseries having an equatorial acetoxy group are fairly stable, so that some of their derivatives could be prepared. 4. By diene synthesis and catalytic hydrogenation, and in the study of the chemical reactions of the product, three of the theoretically possible four isomeric 3-acetoxy-l,2-cyclohexanedicarboxylic acids (VIII), (XXV), and (XXXII) and two isomeric trans-3-hydroxy-l,2-cyclohexanedicarboxylic acids (XXI) and (XXVIII) were obtained.

1. The reaction of the bromohydrin acetate (I) with carbazic ester goes stereospecifically, like its acetolysis, and leads to the cis acetate hydrazone (III) with inversion of configuration. 2. About 30% of the products of the analogous reaction of the bromohydrin (II) have the configuration of the starting compound. It is considered that these products arise as a result of the reaction of the bromohydrin (II) in the diequatorial conformation, whereas under these conditions the diaxial conformer gives products of inverted configuration. 3. The isolation of the monoacetates (III), (V), (VII), and (IX) from the reaction products indicates the high stability of the secondary acetoxy group, as compared with the tertiary, and therefore the occurrence of acyl migration in the 1-acetyl-1,2-cyclohexanediol series. 4. The probable mechanism of the transformations observed is discussed.

1. The behavior of stereoisomeric epoxides of 1-acetyl-4-t-butylcyclohexene-1 under conditions of acetolysis was studied. 2. The 2-acetate of lα-acetyl-4β-t-butylcyclohexane-1β,2α-diol is formed exclusively by axial attack of acetic acid at the C2-reaction center of 1α-acetyl-1β,2β-epoxy-4β-t-butylcyclohexane. 3. In the acetolysis of 1β-acetyl-1α,2α-epoxy-4β-t-butylcyclohexane is formed the 2-acetate of 1,β-acetyl-4β-t-butylcyclohexane-1α,2β-diol, probably by axial attack at the C2 in a “half-tub” conformation and the 1-acetate of 1α-acetyl-4β-t-butylcyclohexane-1β,2α-diol by axial attack at the Cl in the “halfchair” conformation. 4. The complex course of acetolysis of 1β-acetyl-1α,2α-epoxy-4β-t-butylcyclohexane at a higher temperature is caused by partial isomerization of the product of trans-diaxial opening — the tertiary monoacetate of the trans-diol. 5. The 1,2-diacetates of four isomeric 1-acetyl-4-t-butylcyclohexane-1,2-diols were synthesized, and their behavior under conditions of mild basic hydrolysis was examined. 6. The secondary acetoxy group of the diacetate saponifies more easily than the tertiary. During saponification of the diacetates of the ketodiols, a migration of the acyl from the tertiary position to the secondary by an orthoester mechanism is observed.

High crystalline and high molecular weight poly[(acetoxyethyl)oxymethylene] was prepared from β-acetoxypropionaldehyde with use of triethylaluminum and diethylaluminum chloride at low temperature. It was also established by infrared, NMR, and X-ray analyses that even protonic acid such as sulfuric acid could produce the crystalline, isotactic poly[(acetoxyethyl)oxymethylene] at −78°C. It is suggested that the polar acetoxy group participates in the steric control of polymerization and the mechanism is presumed.

The structure of the products of the ozonization of epitorulosol [13S-labda-8(20),14-diene-13,19-diol] (I) has been established. Compound (I) (1 g) was ozonized at −30°C in 100 ml of absolute CH3OH until saturation. The O3 was driven off by nitrogen, 1 ml of (CH3)2S was added at −10°C, and the mixture was stirred for 1 h each at −10, 0, and 20°C and was worked up, and the product (1.13 g) was chromatographed on a column containing 45 g of silica gel. The following were eluted in the order of increasing polarity: 420 mg of 19-hydroxy-8,13;8,14-diepoxy-13S-15,20-bisnorlabdan-14-one (II), mp 141.5–142.5°C (from petroleum ether), [α] D 23 −63° (c 3.1); 255 mg of 8,13;8,14-diepoxy-13S-15,20-bisnorlabdane-14,19-diol (III), characterized in the form of the diacetate (IV) with mp 100–107°C (from petroleum ether); and 117 mg of 19-hydroxy-14,15,20-trisnorlabdane-8,13-dione (V), mp 82–83°C [from petroleum ether-diethyl ether (1:1)], [α] D 26 −40° (c 1.7). The same products but in different ratios were formed on the ozonization of (I) in CH2Cl2-Py or in hexane followed by decomposition of the ozonide by heating with H2O. The [α]D values were measured in CHCl3. Details of the IR and PMR spectra are given.

1. Mercaptolysis and alcoholysis of S,S-diethylacetyl dithiophosphite proceed with replacement of the acetoxy group, leading to the corresponding thiophosphites and acetic acid. 2. S,S-Diethylacetyl dithiophosphite reacts with chloral to form S,S-diethyl-α-acetoxy-α-trichloromethyl dithiophosphonate.

Relative difficulty of saponifying an acetoxy group at C1 and ease of acylation of a hydroxy group in this position as compared with a hydroxy group C10 has been shown for alkaloids with a lycoctonine skeleton. The anomalously easy saponification of a C1-acetoxy group in karakolidine acetates is due to the influence of the neighboring C13-hydroxy group.

It has been shown that with a decrease in the number of substitutents in ring E the ease of pyrolysis of the aconitum alkaloids falls.