The first synthesis of [26, 27-2 H 6] 24-epi-cathasterone 8 via (20 S)-3β-acetoxy-6, 6- (ethylenedioxy)-20-formyl-5α-pregnane 5 starting from stigmasterol is described. The aldehyde 5 was alkylated with lithium butyldimethyl-(E)-2, 3-dimethyl [3, 3, 3, 4, 4, 4-2 H 6] butenylaluminate 6 prepared from 3-[2 H 3] methyl [4, 4, 4-2 H 3] but-1-yne. The structure was determined using spectral data and X-ray crystallographic analysis.
