C17-polyacetylenic alcohols of the toxic plant, Cicuta virosa, virols A (1), B (2), and C (3) were synthesized by stereoselective routes to confirm their stereochemistry and to obtain supply of these compounds for pharmacological study. The syntheses used chiral 3-hydroxy-1-alkyne building blocks, Pd(0)-CuI(I)-catalyzed coupling of acetylene with vinyl chloride, and heterocoupling reaction of acetylene mediated
The absolute stereostructures of cicutoxin (1) and related toxic polyacetylenicalcohols, isocicutoxin (2), and virols A (3) and C (4), from Cicuta virosa were determined on the basis of spectroscopic analysis. The CD exciton chirality method was successfully applied to 4-methoxybenzoates of diyne-conjugated polyenyl alcohol systems. Fatal doses of these compounds on mice are also reported.
A generalstrategytoward the total synthesis of biologically important C17 polyacetylenes family such as virols A and C has been developed, which employed the (R, R)-ProPhenol/Zn complex-catalyzed highly stereoselective direct addition of propiolate to aliphatic aldehydes as the key step for constructing chiral (S)-alkynol units. Besides, chiral alkynol units in other C17 polyacetylenes were also