A Novel Rearrangement of Talatisamine Derivatives

Abstract

Treatment of talatisamine (1) with 6.5% HBr-HOAc at 80°C for 17h gave the desired 8,14,16,18-tetraacetyltalatisamine (2) (81%). Selective hydrolysis of 2 in dioxane-H2O (1:1) under fluxing condition afforded compound 5 (97%). One-pot treatment of 5 with SOCl2-C6H6 at room temperature overnight followed by evaporation to dryness afforded a residue, which reacted with NaBH4 overnight in THF at 50°C to produce the rearrangement alkaloid 8 (10%) besides the expected 7,17-seco products 6 (45%) and 7 (31%).