Synthesis of (±)-Reticuline

Reticuline was synthesized from 4-hydroxy-3-methoxyphenylethylamine and 3-hydroxy- 4-methoxyphenylacetic acid by condensation and O-benzylation to give 2-(3-benzyloxy-4-methoxyphenyl)-N-[2-(4- benzyloxy-3-methoxyphenyl)ethyl]acetamide, which subjected to Bischler-Napieralski reaction with POCl3, N-acylation with methyl chloroformate to give 7-benzyloxy-1-(3-benzyloxy-4-methoxybenzylidene)-6-methoxy-3,4-dihydro-1H- isoquinoline-2-carboxylicacid methyl ester followed by deprotection and reduction with an overall yield of 23%.