A Convenient Method for the Preparation of Secondary Propargylic Ethers. The Reaction of Acetals with 1-Trimethylsilyl-1-alkynes Promoted by the Combined Use of Catalytic Amounts of Tin(IV) Chloride and Zinc Chloride

Article abstract of DOI:10.1246/bcsj.61.4037

In the coexistence of catalytic amounts of SnCl4 and ZnCl2, acetals undergo a coupling with 1-trimethylsilylalkynes to give secondary propargilic ethers in good yields.Similarly, propargilic ethers are directly produced from aldehydes by the treatment with alkoxytrimethylsilanes and 1-trimethylsilylalkynes under the same conditions.This catalyst system also efficiently promotes aldol reaction of silyl enol ethers with acetals or aldehydes, and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones.