HEXACHLOROACETONE-TRIPHENYLPHOSPHINE - MILD REAGENT FOR THE REGIOSELECTIVE AND STEREOSPECIFIC PRODUCTION OF ALLYLIC CHLORIDES FROM THE ALCOHOLS

Allylic alcohols 1-16 react with hexachloroacetone/triphenylphosphine in less than 20 min at 10-15°C to produce excellent yields of the corresponding chlorides. Isolation is accomplished simply by flash distillation. The conversion occurs with total preservation of double bond geometry and with >99% inversion of configuration for optically active alcohol 8. All of the primary and secondary alcohols give predominantly the unrearranged chloride, the α/γ attack ratio being >90: <10 for all but 9, 12, 13, and 14; only the tertiary alcohols give mostly rearranged product. With more highly substituted systems, elimination to diene becomes an important side reaction. © 1979, American Chemical Society. All rights reserved.