A Practical and Stereoselective Synthesis of Cinnamyl Alcohols Bearing alpha-Cyano or alpha-Ester Functional Group from Baylis-Hillman Adducts

摘要

Cinnamyl alcohols bearing ester,acid,or nitrile functional group at the 2-position are very useful synthons for the synthesis of various biologically important compounds.Synthesis of cinnamyl alcohol derivatives from the Baylis-Hillman adducts has been reported by us and other groups.The conversion can be carried out directly by using 20% aqueous sulfuric acid(for the Baylis-Hillman adducts derived from acrylonitrile)or trifluoroacetic acid(for the Baylis-Hillman adducts derived from acrylates).Recently,Basavaiah and coworkers have reported the two-step,one-pot conversion method:TMSOTf-assisted conversion of Baylis-Hillman alcohol into the corresponding primary acetate with acetic anhydride and the following partial hydrolysis with K_2CO_3 in methanol.