Intramolecular thermal cyclization of methyl α-(or β)-eleostearate has been achieved in good yield by the tactical use of sulphur as catalyst. Under relatively mild conditions (∼ 160°), the primary cyclic monomer (methyl cycloeleostearate-I) has been obtained and unambiguously shown to be methyl 5-butyl-1, 3-cyclohexadiene-6-caprylate (IV). Under more energetic conditions (∼ 240°) isomers V and VI are formed at the expense of the primary cyclic ...
