6-VINYLIDENE-HEXAHYDRO-PYRROLIZIN-3-ONE DERIVATIVES AND THEIR PREPARATION METHOD

摘要

Novel 6-vinylidene-hexahydro-pyrrolizin-3-one derivatives and their preparation method are provided to serve intermediates for synthesis of various natural products and development of new drugs by introducing various substituents to the C-6 site. The 6-vinylidene-hexahydro-pyrrolizin-3-one derivatives represented by the formula(1) are provided, wherein R1 and R2 are each independently hydrogen, C1-C6 alkyl group or C1-C6 alkoxy group or form a 5- to 10-membered aliphatic or aromatic hydrocarbon ring together; and the 6-vinylidene-hexahydro-pyrrolizin-3-one derivatives are prepared by subjecting hydroxylactam containing trimethylsilylmethyl-allene to intramolecular acyliminium cyclization in the presence of Lewis acid selected from trimethylsilyl trifluoromethanesulfonate, borontrifluoride etherate and indium halide in a reaction solvent selected from dichloromethane, chloroform and diethylether at 0-25 deg.C.