SYNTHESIS OF MITOSENES FROM N-ARYL-2-(DIPHENYLPHOSPHINYL)PYRROLIDINES

A new route for the construction of the mitosene skeleton was developed using 2-(diphenylphosphinyl)pyrrolidine (2) and 2-methoxy-3-methyl-1,4-benzoquinone (3) as starting materials. Regioselective oxidative addition of 2 to 3 gave 5-substituted pyrrolidinylbenzoquinone 4. Protection of the quinone function by reduction, followed by in-situ reaction with benzyl bromide, gave the bis-benzylated product 5. Using a recently developed route to pyrrolo[1,2-a]indoles, 5 was converted into the protected mitosenes 8. Debenzylation and subsequent oxidation of 8 produced the mitosenes 1 in good yields.