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In this article, a novel synthetic route was described for the total synthesis of Sporiolide B from inexpensive and commercially available starting materials by a concise fourteen-step sequence in 6.50% overall yield. This convergent synthesis utilizes Grignard reaction, Asymmetric dihydroxylation, Yamaguchi macrolactonization and ring closing metathesis as the key steps. [ABSTRACT FROM AUTHOR]

An enantioselective total synthesis of novel gingerol-related compound 4-((3S,5R)-3,5-dihydroxynonadecyl)phenol, an anti-oxidant isolated from the resinous exudates of Chilean desert plants, has been accomplished from a known commercially available 4-(but-3-enyl) phenol by a concise ten-step sequence. In this synthesis, Sharpless asymmetric dihydroxylation, Grignard reaction and Iodine-induced electrophilic cyclization have been applied as key steps. [ABSTRACT FROM AUTHOR]

A concise total synthesis of (-)-Curvularin have been synthesized from commercially available (S)-(−)-propylene epoxide and (3,5-Dimethoxyphenyl)acetic acid. The key steps involved in the synthesis are Vilsmeier-Haack formylation, Grignard reaction, alkylation of 1,3-dithiane and Yamaguchi macrolactonization. [ABSTRACT FROM AUTHOR]

An efficient and concise approach to the total synthesis of Paecilomycins E (1) and F (2), Cochliomycin C (4) and 6-epi-Cochliomycin C (3) is described. The synthesis involves novel route to the synthesis of Paecilomycin E and F and further conversion to Cochliomycin C and 6-epi-Cochliomycin C. Olefin metathesis and base promoted macro lactonization being the key reactions followed by chlorination to achieve target Cochliomycin C and 6-epi-Cochliomycin C. [ABSTRACT FROM AUTHOR]

The total synthesis of 14-membered resorcylic acid macrolide, β-zearalenol, was accomplished starting from commercially available enantiomerically pure propylene oxide and methyl 2,4-dihydroxy-6-methylbenzoate using Grignard reaction, asymmetric dihydroxylation, Yamaguchi macrolactonization, and ring-closing metathesis as key steps. [ABSTRACT FROM AUTHOR]

3-R-Boc-amino-4-(2,4,5-trifluorophenyl)butyric acid (9) was obtained fromL-methionine in six steps with a total yield of 32%. Theα-amino acid segment ofL-methionine was transferred to chiral aziridine by amino protection, reduction, hydroxyl derivation, and cyclization. After ring opening of 2,4,5-trifluoro-phenyl magnesium bromide, the methylthiomethyl group was then hydrolyzed toβ-amino alcohol and oxidized to the targetβ-amino acid. [ABSTRACT FROM AUTHOR]

The main goal of this article is to the present research on the development of ketamine derivatives. The target molecule was a fluoroderivative of ketamine, for which a multistep synthesis has been reported. This novel ketamine derivative, 2-(2-fluorophenyl)-2-methylamino-cyclohexanone, has been called fluoroketamine by our research group. The starting fluorobenzonitrile was reacted with the appropriate Grignard reagent followed by the bromination reaction to obtainα-bromocyclopentyl-(2-fluorophenyl)-ketone. The reaction of the obtained ketone with methylamine at −40 °C then resulted in the formation ofα-hydroxycyclopentyl-(2-flourophenyl)-N-methylamine. Finally, the five-memberd ring cyclopentanol was expanded to the cyclohexylketone by a thermal rearrangement reaction. The HCl salt of the target molecule, which is soluble in water, was obtained by the acidification of the free fluoroketamine with HCl. Preliminary animal tests on mice have shown that the resulting fluoroketamine has some advantages over ketamine in terms of the effective dose and the recovery time. [ABSTRACT FROM AUTHOR]

The synthesis of long-chain 1,ω-diols with orthogonal cleavable protecting groups can be effectively performed with the use of the Grignard coupling reaction, successfully leading to the preparation of novelasymmetricalsingle-chain phosphoglycol-based bolaamphiphiles—a side-product that always occurred during the synthesis ofsymmetricalbolalipids. [Supplementary materials are available for this article. Go to the publisher's online edition ofSynthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] [ABSTRACT FROM AUTHOR]

A total synthesis of (±)-cis-5-hydroxycalamenene 1 has been achieved from tetralone 5, which in turn was prepared from 5-methoxy-α-tetralone 3. Grignard reaction of compound 5 with isopropylmagnesium chloride, followed by dehydration and aromatization, provided the substituted naphthalene 7 whose conversion to (±)-cis-5-hydroxycalamenene 1 was accomplished by demethylation, formylation, and hydrogenation. [ABSTRACT FROM AUTHOR]

An intramolecular cyclization of 17β-acetoxy-3-methoxy-9,11-seco-1,3,5(10)-estratriene-11-oic acid under different Friedel-Crafts reaction conditions is described. [ABSTRACT FROM AUTHOR]

A practical total synthesis of antidepressant (±)-venlafaxine is disclosed. [ABSTRACT FROM AUTHOR]

Synthesis of betamethasone from waste of Thai A. sisalana is described. [ABSTRACT FROM AUTHOR]

The unexpected occurrence of ketones 9 and 16 in addition to expected alcohols 5 and 15 in the synthesis of sesquiterpenes salsolenketone 1 and salsolene oxide 2 during Grignard reactions of the corresponding aldehydes with bromoalkenes under air- and water-free conditions by the Meerwein--Ponndorf--Verley--Oppenauer reaction is reported. The product distribution could be influenced by the amounts of aldehyde used. [ABSTRACT FROM AUTHOR]

Unsymmetrically substituted α-hydroxy ketones possessing isoprenoid units within the molecule were synthesised from commercially available terpene aldehydes. The synthesis was applicable to α,β-unsaturated aldehydes and afforded the respective α-hydroxy-methyl ketones in overall good yield. Tautomerisation of these products did not occur under the conditions of reaction but was observed upon heating. Diastereoisomeric α-hydroxy ketones have been resolved, and X-ray analysis on one of these analogues allowed for the elucidation of the stereochemistry after conversion into its camphanate ester. [ABSTRACT FROM AUTHOR]

A flexible approach to 3-alkyl-2,3-dihydro-1H-isoindolin-1-ones via the reductive-alkylation procedure is described. Present method is versatile in scope, allowing the easy introduction of various C-3 carbon-substituents by Grignard addition to phthalimide. [ABSTRACT FROM AUTHOR]

A convenient and simple one-pot method is described for the synthesis of phosphonites [RP(OEt)2, 1] and H-phosphinates [HP(O)R(OEt), 2] from triethyl phosphite and appropriate Grignard reagents. [ABSTRACT FROM AUTHOR]

A convenient method for the preparation of α-ketoacetal derivatives 2a–g was developed by addition of Grignard reagent (1a–g) to commercially available ethyl diethoxyacetate (3) in 60–96% yield. [ABSTRACT FROM AUTHOR]

The conversion of tetralone 1 to methylketone 7, a valuable intermediate of occidol 8, has been accomplished in four steps (reduction, mesylation, cyanation, and Grignard reaction with methylmagnesium bromide). [ABSTRACT FROM AUTHOR]