Organoboranes. LI. Convenient procedures for the recovery of pinanediol in asymmetric synthesis via one-carbon homologation of boronic esters

Article abstract of DOI:10.1016/0022-328X(88)87067-0

Matteson's asymmetric synthesis via a one-carbon homologation of the pinanediol boronic esters with (dichloromethyl)litihium at -100 deg C results in the insertion of a chloromethyl group into the carbon-carbon bond with > 99percent diastereoselectivity.This procedure makes possible the asymmetric synthesis of the chiral moiety, RR'CH^*B(OR'')2, providing an alternative route to chiral hydroboration for these valuable chiral intermediates.Unfortunately, this method suffers from the remarkable difficulty encountered in the recovery of the pinanediol chiral auxiliary, making this asymmetric synthesis impractical.Fortunately, a systematic study of the problem has uncovered convenient procedures for the recovery of pinanediol from pianendiol boronate esters