Reactions with alkenes of η2-7-oxotetracarbonylmanganese complexes derived from diterpenoids
摘要:
A number of activated 7-oxotetracarbonylmanganese(I) complexes derived from podocarpic acid (1) and from dehydroabietic acid have been coupled with alkenes to give C(14) functionalised derivatives in high yields. Some coupling reactions resulted in cyclization to C(7), forming 4H-acephenanthrylene derivatives in moderate yields. Several modes of activating these manganese complexes towards coupling reactions were investigated; these included oxidative decarbonylation at room temperature, thermal promotion, and palladium-mediation.
Cyclomanganation of diterpenoids; functionalization of C14
作者:Richard C. Cambie、Michael R. Metzler、Peter S. Rutledge、Paul D. Woodgate
DOI:10.1016/0022-328x(90)85462-8
日期:1990.1
Orthomanganated complexes have been made from carbonyl derivatives of the ring-C aromatic diterpenoids podocarpicacid and dehydroabietic acid. Activation of these complexes with Me3NO followed by coupling reactions with various substituted alkenes results in efficient substitution at C14. In some cases a tetracyclic indenol derivative is formed directly. Insertion of an alkyne also leads to cyclopentaannulation