Terpenoids : Part XXIX. Synthesis of dl-trans Veticadinene

Synthesis of (±) \(trans\) veticadinene has been achieved. 1-keto 4-carbethoxy-6-methyl \(trans\)-decalin on alkaline hydrolysis yields 1-keto-4-carboxy-6-methyl-\(trans\)-decalin which is converted to 1-keto-6-methyl-decalyl-4-carboxylic acid chloride, when refluxed with thionyl chloride in benzene. The acid chloride with cadmium dimethyl furnished 1-keto-4-acetyl-6-methyl \(trans\)-decalin. The latter on submission to Wittig reaction with methylenetriphenylphosphorane affords the terpenic hydrocarbon.