Selective desilylation of bis(trimethylsilyl)acetylenes

Substituted acetylenic carbinols such as (2), (5), and (6) are obtained from the reaction of carbonyl compounds with the potassium or lithium salts of trimethylsilyacetylenes; these are prepared either by the in situ cleavage of bis(trimethylsilyl)acetylenes with 1–10 mol% KF–18-crown-6 ether or by the quantitative monodesilylation of bis-silylacetylenes with MeLiLiBr complex.