Reaction of lupane and oleanane triterpenoids with Lawesson's reagent

The reactions of selected triterpenic oxo compounds with Lawesson's reagent were investigated. We examined sulfurization of some oxygen one aldehyde, alpha-hydroxyketones, esters, or anhydrides were chosen. We synthesized 15 new sulfur derivatives, including thioketone 16, dimeric sulfides 17-19, and thiaderivatives 20-22. We also observed unusual transformations, which afforded oxathiaphosphinines 23a, 23b, and dithiaphospholanes 24. The prepared compounds failed to demonstrate any significant cytotoxic activity. (c) 2008 Elsevier Ltd. All rights reserved.