Remote control of Diels-Alder additions. Enantioselective synthesis of (2 R)-1,2,3,4-tetrahydro-2-hydroxy-5,8-dimethoxynaphthalen-2-yl methyl ketone (Wong's anthracycline intermediate) from furfural

Abstract

The enantiomerically pure (1 S,4 R,4′ S,5′ S)-1-(4′,5′-dimethyl-dioxolan-2′-yl)-5,6-dimethylidene-7-oxabicyclo[2.2.1]hept-2-ene derived from the acetal of furfural and (2 S,3 S)-butane-2,3-diol underwent addition to 1-acetylvinyl para-nitrobenzoate in the presence of an excess of t-BuMe 2SiOSO 2CF 3 to yield in 83:17 mixture of two diastereomeric products which was converted into (2 R)-1,2,3,4-tetrahydro-2-hydroxy-5,8-dimethoxynaphthalen-2-yl methyl ketone.