1-Hexyne

1-Hexyne  is a hydrocarbon consisting of a straight six-carbon chain having a terminal alkyne. Its molecular formula is HC2C4H9. A colorless liquid, it is one of three isomers of hexyne. It is used as a reagent in organic synthesis.

Synthesis and reactions
1-Hexyne can be prepared by the reaction of monosodium acetylide with butyl bromide:
 * NaC2H + BrC4H9  ->  HC2C4H9  +  NaBr

Its reactivity illustrates the behavior of terminal alkylacetylenes. The hexyl derivative is common test substrate because it is conveniently volatile. It undergoes deprotonation at C-3 and C-1 with butyl lithium:
 * HC2C4H9 + 2 BuLi  ->  LiC2CH(Li)C3H7  +  2 BuH

This reaction allows alkylation at the 3-position.

Catechol borane adds to 1-hexyne to give the 1-hexenyl borane.

1-Hexyne reacts with diethyl fumarate to produce.