Synthesis of the (1S,2S)- and (1R,2S)-stereoisomers of the respective E- and Z-isomers of ethyl 4-[(2-hydroxycyclohexyl)methyl]phenoxy-3-methyl-2-butenoate using yeast whole cell bioreduction of the parent ketones
Saccharomyces,cerevisiae,strain DBM 2115, was successfully employed in the reduction of the separated Z-and E-isomers of ethyl 4-[(2-oxocyclohexyl)methyl]phenoxy-3-methyl-2-butenoates 1 and 2, in order to prepare the (1S,2S)- and (1R,2S)enantiomers of the corresponding ethyl 4-[(2-hydroxycyclohexyl)methyl]phenoxy-3-methyl-2-butenoates 3-6. The products were obtained with the required absolute configuration: (1S,2S)-3 (ee 98% yield 48%), (1R,2S)-4 lee = >99%; yield 45%), (1S,2S)-5 (ee - 98.5%; yield 47%), and (1R,2S)-6 (ee >99%; chemical yield 44%). (c) 2005 Elsevier Ltd. All rights reserved.
The syntheses of biologically active 2-(4-hydroxybenzyl)-1-cyclohexanone derivatives
作者:Zdeněk Wimmer、Miroslav Romaňuk
DOI:10.1135/cccc19812573
日期:——
The syntheses of various 2-(4-hydroxybenzyl)-1-cyclohexanone derivatives are described in connection with the development of the research of substances with juvenile hormone activity.
-enoic acid ethyl ester (1a/1b-4a/4b; racemic structures) and (1a-4a; enantiopure structures). Cadmium carbonate was used as a promoter of this Koenigs-Knorr reaction, and the products were obtained in 82-92% yields. Deprotection of the carbohydrate functionality of 5a/5b-12a/12b was carefully performed using ethanolysis in the presence of zinc acetate, due to the presence of another ester functionality