Enantioselective epoxidation of crotyl alcohol, followed
by a cuprate mediated methylation, gave a 1:1 mixture of
(2S) -3- methyl -1,2- butanediol and (2R,3S)-2-methy1-1,3-
butanediol. The latter was separated as its 2,4,6-trimethylbenzenesulfonate
derivative and converted via the
iodide to the corresponding phosphonium salt. The separated
butanediol derivatives were independently transformed
to...