Synthesis and Intramolecular Diels-Alder Reaction of 4-Trimethylsiloxy-1, 3, 8-nonatriene

Abstract

Oxy-Cope rearrangement of 4-vinyl-1, .6-heptadien-4-ol [1] at 330°C gave 1, 8-nonadien-4one [4] along with 2, 8-nonadien-4-one [5]. The ketone [4] was converted to the title compound [2] as a mixture of (E)- and (Z)-isomers, by the treatment with LDA and, trimethylsilyl chloride. Alternatively the nonatriene [2] was prepared selectively by the anionic oxy-Cope rearrangement of [1] followed by quenching with trimethylsilyl chloride. Intramolecular Diels-Alder reaction of [2] afforded only cis-3 a-trimethylsiloxy-2, 3, 3 a, 6, 7, 7 a-hexahydro-1 H-indene [3], irrespective of the stereochemistry of [2].