... Introduction of a p-methoxybenzyl group on the nitrogen atom improved the yield for the intramolecular ... In addition, treatment of acetal 12 with H 2 SO 4 −AcOH (1:4 v/v) at 40 ... figure Scheme 4. Preparation of 10 and Synthesis of 1 and Dehydrolennoxamine (3). To examine the e ...