Allyl Alcohol → (R)-Ethyl 3-hydroxypentanoate

Participants

Reaction Steps

Another method to increase the stereoselectivity is using inhibitors to block the enzyme(s) affording the unwanted isomer. A. C. Dahl et al. (1999), Tetrahedron: Asymmetry 10, 551–559, reported the reduction of ethyl-3-oxopentanoate with non heat-treated Baker's yeast and allyl alcohol to ethyl-3(R)-hydroxy-pentanoate (100% yield and 92–93 % ee). When heat-treated Baker's yeast (48° C. for 60 min) was used in combination with allyl alcohol the product was obtained in 80–95% yield and the ee was increased to 98%. However, for the successful reaction a substrate concentration of approximately 1 g/L was used and 250 times yeast relative to substrate, respectively 4 times inhibitor relative to substrate were required.

Provenance & Evidence