Baker's yeast mediated enantioselective synthesis of the bisabolene sesquiterpenes (+)-epijuvabione and (-)-juvabione

Fermenting baker's yeast converts the unsaturated aldehydes 7 and 11 into t he saturated alcohols 8 and 12, respectively. The microbial saturation of t he double bond proceeds in high chemical yields and the stereoselectivity o f the reduction is strongly influenced by the E:Z ratio of the substrate. E nantiopure 8 and 12 are chiral building blocks for the synthesis of bisabol ene sesquiterpenes and their usefulness is shown in the preparation of (+)- epijuvabione 1 and (-)-juvabione 3.