The reductive cyclization of epoxygeranyl acetate (1) was investigated using a catalytic amount of Cp2TiCl with various additives. The newly developed Cp2TiCl-Mn-lutidine.HCl-BEt3 system was found to be as effective as the reported stoichiometric system to afford the cyclized dehydro products 4 and 5 with 72% selectivity. (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis of (±)-karahana ether and karahanaenone by selective cyclization of 6,7-epoxygeranyl acetate
作者:Alejandro F. Barrero、Enrique J. Alvarez-Manzaneda、P.Linares Palomino
DOI:10.1016/s0040-4020(01)89332-7
日期:1994.1
Efficient methods for preparing (±)-karahanaether (1b) and karahanaenine (2) from 6,7-epoxygeranyl acetate(3), by Lewis-acid-catalyzed electrophillic cyclization, are described.