Stereochemical aspects of the reaction of lithio(1-methyl-2-propenyl)diphenylphosphine oxide with .beta.-substituted aldehydes. Short syntheses of (-)-.alpha.-selinene and (+)-.alpha.-helmiscapene
Stereochemical aspects of the reaction of lithio(1-methyl-2-propenyl)diphenylphosphine oxide with .beta.-substituted aldehydes. Short syntheses of (-)-.alpha.-selinene and (+)-.alpha.-helmiscapene