Stereoselective syntheses of deuterium labelled marmesins; valuable metabolic probes for mechanistic studies in furanocoumarin biosynthesis

Article abstract of DOI:10.1016/S0040-4020(97)10237-X

Stereoselective syntheses of deuterium labelled marmesins 3a-3e as metabolic probes for biosynthetic studies are described. Starting from iodo-umbelliferone (5), the title compounds were readily available by copper catalysed alkylation-cyclisation and subsequent transfer-hydrogenation of the resulting furanocoumarins 6a-6e. The bioconversion of marmesin by a microsomal preparation of A. majus yielded psoralene (4) and acetone in a single step and proceeded as a syn-elimination of the alkoxy-substituent together with a single hydrogen atom from a vicinal carbon atom (β-cleavage).