A novel approach to the enantioselective formal synthesis of pumiliotoxin 251D
作者:Yike Ni、Gang Zhao、Yu Ding
DOI:10.1039/b004450o
日期:——
An efficient enantioselective synthesis of the indolizidine framework 9 of pumiliotoxin 251D in good yield by using a Lewis acid (cat.)-promoted diastereoselective addition of ethyl lithiopropiolate to ketone 7 derived from L-proline as a key step is reported. Hydrogenation of the addition product 8a gave the desired lactam 9. At the same time the 8-epimer of 9 was synthesized for the first time.