110625-77-9Relevant articles and documents
Biohydrogenation of Unsaturated Compounds by Saccharomyces cerevisiae. Part 1. Stereochemical Aspects of the Reaction and Preparation of Useful Bifunctional Chiral Synthons
Ferraboschi, Patrizia,Grisenti, Paride,Casati, Rosangela,Fiecchi, Alberto,Santaniello, Enzo
, p. 1743 - 1748 (2007/10/02)
Ethyl 4,4-dimethoxy-3-methylbut-2-enoate (1; R=CO2Et) has been prepared as a mixture of (E)- and (Z)-isomers, the (E)/(Z) ratio depending on the base used.Each isomeric mixture of (1a) and (1b) has been used as substrate for biohydrogenation with fermenting Saccharomyces cerevisiae (baker's yeast) and the (Z)-isomer seems to be the preferred substrate. (E)-Unsaturated alcohols such as (3a) and (5d) are not reduced to the corresponding saturated hydroxy derivatives by baker's yeast.The (E)-aldehyde (3c) and its acetal (3d) are mainly reduced to the corresponding (E)-alcohol (3a), the saturated hydroxy ester (2a) being formed to a minor extent, especially with (3d).In contrast, biohydrogenation is also successful with the (E)-isomers of compounds (3e), (3f), and (3b) (R2=alkyl or alkenyl).If the allylic oxygenated group to be reduced is not α-methyl substituted, reduction to the corresponding saturated alcohols readily occurs with the (E)-isomers as in the case of (5f).For this last biohydrogenation, the stereochemistry of the methyl-bearing carbon has been established by chemical correlations.The α,β-disubstituted allylic acetal (6a) is not biohydrogenated by the yeast, but a mixture of unsaturated hydroxy ester (6b) and γ-hydroxy lactone (8) is recovered from the incubation.
