Preparation and sodium-ammonia reduction of some conjugated alkadienes

Abstract

A series of alkadienes was prepared by the dehydration of unsaturated c7 and c8 alcohols. The dienes were separated by G .P.C. techniques and identified by their NMR and IR spectra. The UV data of the conjugated dienes was also recorded. The dehydration of 4-ethyl-l-hexen-4-ol gave three dienes, 4-ethyl-l, 3-hexadiene, 4-ethyl-l, 4-hexadiene and 3-ethyl-2, 4-hexadiene. The dehydration of 4-methyl-l-hexen-4-ol gave four dienes, 4-methyl-1, 4-hexadiene, 2-ethyl-1, 4-pentadiene, 4-methyl-l, 3-hexadiene and 3-methyl-2, 4-hexadiene. The dehydration of 4-octen-2-ol gave 1, 3-octadiene and 2, 4-octadiene in about equal amounts. The sodium-ammonia reduction products of 2, 5-dimethyl-2, 4-hexadiene, 1, 3-octadiene, and 2, 4-octadiene were determined. The reduction of 2, 5-dimethyl-2, 4-hexadiene gave both the symmetrical and unsymmetrical olefin as reduction products. One reduction of 1, 3-octadiene gave 2-octene. The other reductions of 1, 3-octadiene and 2, 4-octadiene gave mixtures of olefins as their monomeric products.