A new protocol for regio-and stereocontrolled aldol reactions through the conjugate addition of dialkylboranes to. alpha.,. beta.-unsaturated ketones

…, C Trombini, A Umani-Ronchi

Index: Boldrini, Gian Paolo; Bortolotti, Michele; Mancini, Fabrizio; Tagliavini, Emilio; Trombini, Claudio; Umani-Ronchi, Achille Journal of Organic Chemistry, 1991 , vol. 56, # 20 p. 5820 - 5826

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Citation Number: 34

Abstract

A onepot, two-step procedure, consisting of the 1, 4addition of &lboranes to &substituted (8)- a&uneaturated ketones followed by the reaction of the resulting configurationally pure (2)- (viny1oxy) boranes with aldehydes, is reported. The overall process corresponds to a regio- and stereocontrolled aldol addition of an unsymmetrical ketone to an aldehyde. A concerted 1, Caddition mechanism accounts for the stereochemical outcome of the hydroboration ...