Synthesis of 4- and 5-(1,3-dimethylbut-2-enylthio)-2,6-dimethylocta-2,6-diene, models for sulphur crosslinks in natural rubber

Abstract

The title sulphides (14) and (8) have been prepared by treatment of 2,6- and 3,7-dimethylocta-2,6-dien-4-ol (11) and (5) with N-chlorosuccinimide–triphenylphosphine, followed by reaction of the resulting isomeric chloride mixtures with sodium 4-methylpent-3-ene-2-thiolate. The sulphides were isolated by reverse-phase h.p.l.c. The syntheses of the homoallylic aldehydes (3) and (4), which reacted with vinylic Grignard reagents to form the required dienols, are also described.