Metal-ammonia reduction of chrysene through the hexahydro stage proceeds regiospecifically via 5, 6-dihydro-(1) and 4b, 5, 6, 12-tetrahydro-(2) to 4b, 5, 6, 10b, 11, 12- hexahydrochrysene (3). Existence in liquid ammonia of stable monoanionic intermediates related to 1 and 2, but not 3, is demonstrated by reductive methylation. Cis stereoselectivity observed in reduction of both 2 and 5, 6, 11, 12-tetrahydrochrysene to 3 is dependent ...
