Enantioselective alkylative double ring opening of epoxides: synthesis of enantioenriched unsaturated diols and amino alcohols

Enantioselective generation and intermolecular trapping of a lithium carbenoid occurs in the reaction of epoxides of 2,5-dihydrofuran, 2,5-dihydropyrrole, and oxa- and aza-bicyclo[n.2.1]alkenes (n = 2, 3) with organolithium compounds in the presence of external chiral ligands. This methodology leads to the synthesis of important unsaturated diol and amino alcohol functionality (see scheme; tertbutoxycarbonyl).