PHOSGENATION OF BENZYLTETRAHYDROISOQUINOLINES. A NEW METHOD OF BERBINES AND BERBIN-8-ONES SYNTHESIS

Article abstract of DOI:10.1016/S0040-4020(01)83481-5

A novel synthesis of the berbine ring skeleton by the way of the berbin-8-ones is reported.Treatment of 1-benzyl-1,2,3,4-tetrahydroisoquinolines 1a-d with phosgene gas gave a new series of N-chloroformyl derivatives 2a-d.Intramolecular ring closure of the