Abstract
Starting from lanosteryl acetate (1b), we synthesized twelve lanosterol analogs (cf. Chart 1-3 ; 9, 11, 14, 16, 18a, 19, 26, 27a, 28, 29, 30, 32) with different sizes of side chain and 20-iso-24-dihydrolanosterol (37), for biological studies. The analogs have shorter side chains than 1b except for the 24-ethylidene derivative (19) and 37. 20-Iso-24-di-hydrolanosterol (37) was prepared via 20-iso-22-dehydro-24-dihydrolanosterol [obtained by the Wittig reaction of 20R, S-aldehyde mixture (6, 33) with isoamyl triphenylphosphonium iodide, followed by column chromatographic separation].
