A regiospecific synthesis of protoberberine alkaloids

…, J Poplawski, BC Nalliah, DB MacLean

Index: Kiparissides, Zinovia; Fichtner, Robert H.; Poplawski, Janusz; Nalliah, Bala C.; MacLean, David B. Canadian Journal of Chemistry, 1980 , vol. 58, p. 2770 - 2779

Full Text: HTML

Citation Number: 31

Abstract

The protoberberine skeleton has been prepared in two steps from N-benzyl-3, 4- dihydroisoquinolinium salts. Treatment of the salts with the anion of methyl methylthiomethylsulfoxide yields mixtures of diastereomeric adducts that cyclize on heating with concentrated hydrochloric acid to dihydroprotoberberines. The latter compounds may be reduced to their tetrahydro analogues with sodium borohydride, oxidized to ...