Pure Appl. Chem., 2004, Vol. 76, No. 3, pp. 651-656
doi:10.1351/pac200476030651
Recent advances in transition metal-catalyzed or -mediated cyclization of 2,3-allenoic acids: New methodologies for the synthesis of butenolides*
S. Ma
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China
Abstract:
The cyclization reactions of 2,3-allenoic acids or their salts with optically active bases affording butenolides are discussed. Two reaction pathways were observed: (1) intermolecular carbometallation-intramolecular allylation; (2) cyclic oxymetallation-reductive elimination. High efficiency of chirality transfer was realized with the latter case.