Synthesis and evaluation of atropos dihydro-5H-dibenzazepinium halide PTCs derived from α-methylbenzylamine

A short synthetic route to diastereoisomeric atropos dihydro-5H-dibenz[c,e]azepinium salts via reaction of a single enantiomer of (R)-α-methylbenzylamine with a racemic atropos biphenol derivative is described. Compounds prepared via this approach are used to provide strong evidence that structurally related tropos dihydro-5H-dibenz[c,e]azepinium salts preferentially react via a single conformation in PTC reactions involving glycine imine enolates.