Syntheses and stereochemical assignment of toxic C-17-polyacetylenic alcohols, virols A, B, and C, isolated from water hemlock (Cicuta virosa)

In the course of our study on neurotoxic C-17-polyacetylenic alcohols of th e toxic plant, Cicuta virosa, virols A (1), B (2), and C (3) were synthesis ed by stereoselective: routes to confirm their stereochemistry and to obtai n supply of these compounds for pharmacological study. The syntheses used c hiral 3-hydroxy-1-alkyne building blocks, Pd(0)- Cul(l)-catalyzed coupling of acetylene with vinyl chloride, and heterocoupling reaction of acetylene mediated by Cul. As a result, the absolute configuration of the stereogenic center of virols A(1), B (2), and C (3)was confirmed as S, S, and S, respe ctively. (C) 1999 Elsevier Science Ltd. All rights reserved.