Astaxanthin

Synthesis of stereodefined polysubstituted olefins. 1. Sequential intermolecular reactions involving selective, stepwise insertion of Pd(0) into allylic and vinylic halide bonds. The stereoselective synthesis of disubstituted olefins.

Organ MG, Cooper JT, Rogers LR, Soleymanzadeh F, Paul T.

Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3. organ@yorku.ca

Palladium-catalyzed allylic substitution and cross-coupling reactions have been combined into a sequential procedure to provide a range of disubstituted olefin products starting from two-, three-, and four-carbon common olefin templates. Diverse application of this template strategy is demonstrated in a variety of model studies and in a parallel synthesis (combinatorial) approach to prepare an allylic amine molecular library. An approach toward the preparation of astaxanthin beta-D-diglucoside, an interesting antioxidant whose total synthesis has yet to be reported, using the olefin-template approach is also discussed.

PMID: 11073604 [PubMed - indexed for MEDLINE]