Efficient Synthesis of Dicycloalkylacetylenes: 1,2- Dicyclopropylethyne and (cyclopropylethynyl)cyclobutane (Preprint)

摘要

Lithium acetylides, generated from terminal acetylenes with n-BuLi in THF at -70 degrees C, react chemoselectively with omega-haloalkyl tosylate in the presence of 10 mole % of Bu4I at 70 degrees C to furnish omega-haloalkyl acetylenes in very good yields. The omega-haloalkyl acetylenes were subject to intra-molecular alkylation with LDA to provide dicycloalkylethyne.