- A NOVEL APPROACH TO THE SYNTHESIS OF CHIRAL EPOXIDES AND ALLYLIC ALCOHOLS BY THE USE OF OPTICALLY ACTIVE p-TOLYL SULFINYL GROUP AS A CHIRAL AUXILILIARY
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A Novel synthesis of chiral epoxides and allylic alcohols was realized from (-)-chloromethyl p-tolyl sulfoxide and carbonyl compounds through the α,β-epoxy sulfoxides.The procedure and a stereochemistry of the asymmetric induction of the reaction are repo
- Satoh, Tsuyoshi,Oohara, Teruhiko,Yamakawa, Koji
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- Reagent-controlled asymmetric homologation of boronic esters by enantioenriched main-group chiral carbenoids
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Putative enantioenriched carbenoid species, (R)-1-chloro-2- phenylethylmagnesium chloride (9) and (S)-1-chloro-2-phenylethyllithium (26), generated in situ by sulfoxide ligand exchange from (-)-(Rs,R)-1- chloro-2-phenylethyl p-tolyl sulfoxide (8), effected the stereocontrolled homologation of boronic esters. sec-Alcohols derived from the product boronates by oxidation with basic hydrogen peroxide exhibited % ee closely approaching that of sulfoxide 8 in examples employing Li-carbenoid 26.
- Blakemore, Paul R.,Marsden, Stephen P.,Vater, Huw D.
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p. 773 - 776
(2007/10/03)
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- Highly enantiomerically enriched α-haloalkyl grignard reagents
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α-Chloro- and α-bromoalkyl Grignard reagents 11 and 30 with > 97% ee (enantiomeric excess) were generated by a sulfoxide/magnesium exchange reaction from the enantiomerically and diastereomerically pure sulfoxides 25 and 27. The resulting α-haloalkyl Grig
- Hoffmann, Reinhard W.,Nell, Peter G.,Leo, Roland,Harms, Klaus
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p. 3359 - 3365
(2007/10/03)
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- A Novel Approach to the Asymmetric Synthesis of Epoxides, Allylic Alcohols, α-Amino Ketones, and α-Amino Aldehydes from Carbonyl Compounds through α,β-Epoxy Sulfoxides Using the Optically Active p-Tolylsulfinyl Group To Induce Chirality
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A practical and relatively inexpensive procedure for the preparation of (-)-chloromethyl p-tolyl sulfoxide of high optical purity was accomplished by the chlorination of optically pure (+)-methyl p-tolyl sulfoxide with N-chlorosuccinimide in the presence of K2CO3.The (-)-chloromethyl p-tolyl sulfoxide was alkylated to give a diastereomeric mixture of (-)-1-chloroalkyl p-tolyl sulfoxides.Addition of the anion derived from these sulfoxides to ketones or aldehydes afforded chlorohydrins in quite good yields with complete 1,2-asymmetric induction.Treatment of these chlorohydrins with a base gave optically active α,β-epoxy sulfoxides.On treatment with n-BuLi, the α,β-epoxy sulfoxides gave epoxides or allylic alcohols of high optical purity.This novel procedure was applied to a short synthesis of optically active (+)-disparlure, the sex attractant of the female gypsy moth.Aminolysis of the α,β-epoxy sulfoxides gave optically active α-amino ketones and α-amino aldehydes in quite good yields.
- Satoh, Tsuyoshi,Oohara, Teruhiko,Ueda, Yoshiko,Yamakawa, Koji
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p. 3130 - 3136
(2007/10/02)
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- THE PRACTICAL PROCEDURE FOR A PREPARATION OF 1-CHLOROALKYL p-TOLYL SULFOXIDES IN HIGH OPTICALLY ACTIVE FORM: A VERY SHORT SYNTHESIS OF OPTICALLY ACTIVE DISPARLURE
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A chlorination of optically active alkyl p-tolyl sulfoxides with N-chlorosuccinimide in dichloromethane in the presence of potassium carbonate afforded optically active 1-chloroalkyl p-tolyl sulfoxides in 87-94percent ee (88-94percent chemical yields).The optically active chloroalkyl sulfoxide was applied to a synthesis of optically active (+)-disparlure.
- Satoh, Tsuyoshi,Oohara, Teruhiko,Ueda, Yoshiko,Yamakawa, Koji
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p. 313 - 316
(2007/10/02)
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