An improved route to an intermediate in podophyllotoxin synthesis
作者:William S. Murphy、Sompong Wattanasin
DOI:10.1039/c39800000262
日期:——
cyclopropanyl keto-ester epimers (4) and (5); both stannic chloride and boron trifluoride etherate in nitromethane catalyse the stereoselective cyclisation of this mixture to the tetralone (2), the known podophyllotoxin precursor, in 51% overall yield.