Reductions of alpha,beta-unsaturated ketones by NaBH4 or YaBH(4)+CoCl2: Selectivity control by water or by aqueous micellar solutions

Operationally simple and environmentally benign procedures have been develo ped to selectively reduce different alpha,beta-unsaturated ketones, 4,4-dim ethylcyclohex-2-ene-1-one (1), isophorone (2), benzylideneacetone (3), chal cone (4) by NaBH4 or by the system NaBH4 + CoCl2. Alternative reaction medi a to the extensively used MeOH have been explored, and new procedures take advantage of the acceleration and chemoselectivity induced by water or by a queous micellar solutions. It was possible to selectively and quantitativel y afford pure products of 1,2 and of 1,4 reduction as well as the totally r educed compounds (yield and selectivity >90%) by simple changes in the expe rimental conditions.