A simple and stereoselective synthesis of Des-A-B-aromatic corticoids via intramolecular cycloaddition: potential intermediates for the synthesis of corticoids

Abstract

Intramolecular cycloaddition reaction of the o-quinodimathane (7) derived thermolysis of 3-isopropenyl-1-(4-methoxybenzocyclobuten-1-yl)-4-methylpent-4-en-3-ol (6) gave stereoselectively trans-3α-hydroxy-3β-isopropenyl-7-methoxy-3aβ-methyl-2,3,3a,4,5,9b-hexahydro-1H-benz[e]indene (8), which was efficiently converted into the bismethylenedioxy derivative (3) of the des-A-B-aromatic corticoid (10)via(9).