Cationic polymerization of bis(1‐alkylvinyl)benzenes and related monomers, 4. Synthesis of monomers with long alkyl side chains

Abstract

Homologues of the series 1,4-bis(2-methyl-2-alkenyl)benzene (6) are potential monomers for the systematic synthesis of alkyl-substituted polyindans. The first five homologues were prepared by Wittig-synthesis, starting from 1 ,Cdiacetylbenzene (5) and the corresponding n-alkyltriphenylphosphonium bromide (3). Three double-bond isomers were qualitatively and quantitatively identified by 'H and I3C NMR spectroscopy. The reaction conditions chosen favour Z-olefination, and the selectivity ratio of 2-and E-olefin formation in each step was estimated. a) Part 3: cf. ref.') b,