Stereocontrolled synthesis of exocyclic olefins using arene tricarbonyl chromium complex-catalyzed hydrogenation. I. Efficient synthesis of carbacyclin and its analogs.
An efficient synthesis of carbacyclin and its analogs (2-7) is described in which the stereospecific 1,4-hydrogenation of a 1,3-diene to an internal monoene plays a key role. That is, arene.Cr(CO)3 complex-catalyzed 1,4-hydrogenation of the dienes 13 and 58, obtainable from the Corey lactone in good yields, under high H2 pressure afforded the exocyclicolefins 14 and 61 stereospecifically in excellent