Organoiron complexes in organic synthesis. Part 23. New strategies for steroid and aphidicolane synthesis

Abstract

Methodologyallowing the application of tricarbonyl(4-methoxy-1 -methylcyclohexadienylium)iron hexafluorophosphate(1a) as a ring A synthon for the construction of D-homoaromatic steroid derivatives is described, via its regiospecific reaction with the potassium enolate of methyl 6-methoxy-1-oxo-1,2,3,4-tetrahydronaphthalene-2-carboxylate. A model study is presented towards the conversion of (1a) into the tetracyclic diterpene aphidicolin (12), in which the complex is converted in 12 steps to the spirotricyclic compound (46).