Reactions of 3-phenylthiobut-3-en-2-one. Part 4. Novel and efficient synthesis of 7-hydroxycalamenene, ferruginol, and D-homoestrone

Abstract

The annelation reaction of 3-phenylthiobut-3-en-2-one with carvomenthone (1)gives 8a-hydroxy-4α-isopropyl-1-methyl-6-phenylthioperhydrpnaphthalen-7-one (2), which is converted into 7-hydroxy-calamenene (4) by subsequent dehydration, methylation, and aromatisation in good yield. Ferruginol (13) and D-homoestrone (16) are prepared similarly by this annelation method starting from naphthalenone (9) and phenanthrenone (14), respectively. In addition, the reactions of 3-phenylthiobut-3-en-2-one with (14) and with cyclohex-2-en-1 -one in the presence of liquid ammonia afford annelated pyridine derivatives, the azachrysene (21), and the tetrahydroquinoline (23).