1,1,2,2,7,7,8,8-Octaethoxyocta-3,5-diyne

Abstract

1,1,2,2,7,7,8,8-Octaethoxyocta-3,5-diyne has been observed as a minor product in several syntheses utilizing 3,3,4,4-tetraethoxybut-1-yne (TEB) as starting material. In order to access this highly functionalized diyne, we have developed a procedure that provides the title compound in excellent yield.

Formation of an Isomeric Mixture of Dienynes Instead of a Diallene

“…Since the synthesis of 3,3,4,4-tetraethoxybutyne (TEB) was reported some 15 years ago [1][2][3], many of its chemical properties have been uncovered and used to prepare a range of chemical compounds with rich structural diversity [4][5][6][7][8][9][10][11][12][13][14][15]. Among the most densely functionalized molecules made is 1,1,2,2,7,7,8,8-octaethoxyocta-3,5-diyne (1), which has one ketal moiety in propargylic position to each of the triple bonds [16]. The compound therefore belongs to a group of compounds that can undergo S N 2 reactions by nucleophilic attack of the triple bond, which is accompanied by C-C bond migration that leads to the release of a leaving group from the propargylic carbon and formation of an allene moiety.…”