Electrochemical Preparation of Alkynedial Tetramethyl Acetals

Abstract

Tetramethyl acetals of alkynedials were prepared by anodic oxidation of corresponding alkyne-1,ω-diols (C4 and C6) in trimethyl orthoformate on glassy carbone anode in 80% yield. 1,1,4,4-Tetramethoxybut-2-yne (2a) can be prepared by this one-step procedure from but-2-yne-1,4-diol (1a) instead of a multistep chemical procedure starting from 2,5-dimethoxyfuran. Propargyl alcohol (3) can be similarly anodically oxidized in trimethyl orthoformate giving dimethyl acetal of propynal (4) in 85% yield.