Arene cis-dihydrodiols: useful precursors for the preparation of analogues of the anti-tumour agent, 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC).

The synthesis of 6-epi-COTC, a diastereoisomer of Streptomyces metabolite 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC), is described. The anti-cancer activities of the novel analogue, in racemic and enantiomerically pure forms, are presented.