Potentially carcinogenic cyclopenta[a]phenanthrenes (1,2-cyclopentenophenanthrenes). Part II. Derivatives containing further unsaturation in ring D

Abstract

Substituted 17-methyl-15H-cyclopenta[a]phenanthrenes have been prepared from the corresponding 15,16-dihydro-17-ketones by the Grignard reaction, and reduced to the analogues of the Diels hydrocarbon. The 15,16-dihydro-17-methylene-derivative (unsubstituted) was obtained by the Witting reaction. Elimination from the 17-toluene-p-sulphonyloxy-compound at 170° gave the Δ¹⁵– 17H-compound (A), but at 100° the Δ¹⁶– 15H-isomer was formed. Base-catalysed condensation of (A) with acetone and aryl aldehydes yielded 17-substituted-methylene derivatives. The chemical shifts of protones attached to ring D in these compounds are listed.