Allyl Alcohol → (R)-Ethyl 3-hydroxypentanoate

HRID 460506Notes

Reaction equation

HRID 460506 reaction equation
[CH2:1]([O:3][C:4](=[O:10])[CH2:5][C:6](=[O:9])[CH2:7][CH3:8])[CH3:2].C(O)C=C>>[CH2:1]([O:3][C:4](=[O:10])[CH2:5][C@H:6]([OH:9])[CH2:7][CH3:8])[CH3:2]

Participants

3

Reactant 2

HCID 7858Allyl AlcoholHCID 78656Ethyl 3-oxovalerate

Product 1

HCID 10855610(R)-Ethyl 3-hydroxypentanoateYield 100%

Procedure

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.

Workup

  1. temperatureAnother method to increase the stereoselectivity
  2. customaffording the unwanted isomer

Sources & evidence

ORD record
ord-83ec19782214476f8b8bfdd3c0e0bca3
Source dataset
uspto-grants-2007_03
Patent number
US07196234B2

Reaction notes

Loading…