Organic Letters 2006-06-08

Total synthesis of (-)-8-O-methyltetrangomycin (MM 47755).

Christian Kesenheimer, Ulrich Groth

Index: Org. Lett. 8(12) , 2507-10, (2006)

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Abstract

A stereoselective total synthesis of the natural antibiotic (-)-8-O-methyltetrangomycin 1 is reported. The essential steps for this convergent synthesis are the transformation of a geraniol epoxide into a chiral octadiyne derivative, which was converted into a triyne. The cobalt-mediated [2+2+2] cycloaddition of the triyne led to a benz[a]anthracene system, which was oxidized with Ag(Py)(2)MnO(4) to a benz[a]anthraquinone. Deprotection with aqueous HF in acetonitrile and photooxidation afforded the desired product (-)-1. [reaction: see text]