摘要:
                                Isolation of the morpholine enamine of indolizidin-7-one as a pure regioisomer allowed the synthesis of 3,4,5,7,8,9,9a,10-octahydro-2H-pyrano[3,2-f]indolizines and gave an entry into a new heterocyclic series, the 6H-[1]benzopyrano[3,2-f]indolizines.