Abstract
3,3,4,4-Tetraethoxybut-1-yne acetylide (TEB–) reacted with several epoxides under a variety of conditions. When the acetylide
counterion was lithium, nothing happened in the absence of ammonia and HMPA, but reaction
of TEBLi with a mixture of oxirane and BF3 (oxirane/BF3 addition to the acetylide) followed by hydrolysis gave the expected homopropargylic
alcohols in about 80% yield. When the counterion was MgBr+, oxirane-to-aldehyde rearrangement took place before the acetylide reacted and gave
propargylic alcohols in good yields in all cases except one; the only exception was
ethylene oxide, which gave the homopropargylic alcohol in 70% yield.
Key words
epoxides - acetylides - counterions - oxirane rearrangement - homopropargylic alcohol
- propargylic alcohols