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Asymmetric Dihydroxylation of β,γ‐Unsaturated Carboxylic Esterswith Trisubstituted C=C Bonds – Enantioselective Syntheses of Trisubstituted γ‐Butyrolactones
Author(s) -
Kapferer Tobias,
Brückner Reinhard
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500963
Subject(s) - chemistry , dihydroxylation , sharpless asymmetric dihydroxylation , enantioselective synthesis , reagent , double bond , lactone , enantiomer , stereochemistry , organic chemistry , catalysis
β,γ‐Unsaturated esters with stereodefined trisubstitued C=C double bonds were prepared by the Arndt–Eistert homologation of α,β‐unsaturated carboxyl halides, by two‐step methoxycarbonylation of allylbarium reagents, by deconjugation of α,β‐unsaturated esters, and by Horner–Wadsworth–Emmons variants of the Stobbe condensation. Sharpless asymmetric dihydroxylation of the β,γ‐unsaturated esters, followed by spontaneous cyclization, afforded β‐hydroxy‐γ‐lactones in moderate to good yields and with enantiomeric excesses of up to 97 %. Similarly, tetrahydroxy‐γ‐lactones were obtained from diunsaturated esters; these lactones were converted into a bislactone and an unsaturated β‐hydroxy γ‐lactone. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)