An aryne route to laureline, and related topics
Abstract
A route to laureline (IX), involving as key steps treatment of 1-(3-bromo-4-methoxybenzyl)-1,2,3,4-tetrahydro-2-methyl-6,7-methylenedioxyisoquinoline (IIa) with potassamide in liquid ammonia followed by Pschorr ringclosure, is described, together with details of the synthesis of compound (IIa) and related compounds from the appropriate phenethylamines and 3-bromo-4-methoxyphenylacetic acid.
The problem of polymerisation which supervenes in amine-catalysed condensation of aromatic aldehydes with nitromethane contaminated with methyl nitrite is noted.