Synthesis of Tricyclo[4.4.0.02,7]decane Derivatives from Tricyclo[4.1.0.02,7]heptane Precursors

Resumo

Tricyclo[4.1.0.0^2,7]heptane and 1-phenyltricyclo[4.1.0.0^2,7]heptane reacted with 2,3-bis(benzenesulfonyl)propene in boiling toluene (20–24 h) in the presence of benzoyl peroxide via trans-selective cleavage of the C¹–C⁷ central bicyclobutane bond to give 6(7)-syn-benzenesulfonyl-7(6)-exo-[2-(benzenesulfonyl)prop-2-en-1-yl]bicyclo[3.1.1]heptane derivatives. The latter underwent cyclization to 1,9- and 7,9-bis(benzenesulfonyl)tricyclo[4.4.0.0^2,7]decane derivatives by the action of potassium tert-butoxide in dioxane at 50°C as a result of intramolecular Michael addition. Heating of the cyclization products in dioxane at 100°C in the presence of potassium tert-butoxide resulted in elimination of benzenesulfinic acid molecule with the formation of mixtures of two isomeric benzenesulfonyl-substituted tricyclo[4.4.0.0^2,7]dec-3-enes.