Synthesis of 3,4-bridged indoles by photocyclisation reactions. Part 2. Photocyclisation of halogenoacetyl tryptophol derivatives and α-chloro indol-3-ylalkanoate esters
作者:Anthony L. Beck、Mark Mascal、Christopher J. Moody、William J. Coates
DOI:10.1039/p19920000813
日期:——
Irradiation of the trichloroacetates 2, 4 and 5, derived from the corresponding tryptophols, in methanolic acetonitrile results in photocyclisation to the indole 4-position, and the formation of the pyrrolobenzoxocines 9-11. Attempted photocyclisation of the 'reversed' alpha-chloro esters 15a, 15b and 18 was thwarted by readily occurring elimination of HCl, although the dimethyl compound 15c did cyclise to give the cycloheptaindole 20 upon irradiation in acetonitrile.