Condensed cyclic and bridged-ring systems. Part 15. Acid-catalysed intramolecular alkylations in 1-diazoacetyl-1,2,3,4-tetrahydro-9-methoxy-1-methylphenanthrenes

Abstract

The acid-catalysed reaction of the 1-diazoacetyltetrahydrophenanthrene 1a and the three new related diazoketones 1b–d gave, in addition to the respective bridged ketones 2a–d and the pentaleno annelated ketones 3a–d, the acephenanthrones 4a–d, which were also prepared in excellent yield by the rhodium(II) acetate-induced reaction of the diazoketones.