Reactions of 2-acyl-1,3-dithianes with α,β-unsaturated ketones: Simple preparation of cyclohexendione monoacetals
作者:Philip C. Bulman Page、Shaun A. Harkin、Allan P. Marchington
DOI:10.1016/s0040-4039(01)93945-0
日期:1989.1
2-Acyl-1,3-dithianes undergo efficient Lewis acid-catalysed addition to α,β-unsaturated ketones giving δ-diketones which suffer intramolecular aldol reaction to produce cyclohex-2-en-1,4-dione monoacetals and/or cyclohex-3-en-1,2-dione monoacetals.
ENANTIOSELECTIVE SYNTHESIS OF α-HYDROXYTHIOACETALS BY THE BAKER’S YEAST REDUCTION OF α-KETOTHIOACETALS
作者:Tamotsu Fujisawa、Eiji Kojima、Toshiyuki Itoh、Toshio Sato
DOI:10.1246/cl.1985.1751
日期:1985.11.5
Asymmetric reduction of a-ketothioacetals was achieved by fermenting baker’s yeast to afford optically pure α-hydroxythioacetals which play as equivalents of valuable α-hydroxy aldehydes. The utility of the present method was demonstrated in the stereo-selective syntheses of (4S,5S)- and (4S,5R)-4,5-dihydroxydecanoic acid γ-lactones from (S)-(−)-1-(1,3-dithian-2-yl)-1,4-butanediol.