PROCEDE DE PREPARATION DE DERIVES DE L'ACIDE VINCAMINIQUE PAR TRANSPOSITION OXYDATIVE DE LA TABERSONINE OU DE LA DIHYDROTABERSONINE

摘要

The invention relates to a novel process for the preparation of vincamic acid esters, specifically 17,18-didehydrovincamic acid esters, and the corresponding 14-epi compounds by oxidative rearrangement of, respectively, tabersonic acid esters and dihydrotabersonic acid esters, which is characterised in that these starting substances are treated with at least equimolar amounts of dialkyl peroxides formed from dibasic organic carboxylic acids or inorganic acids, or with salts thereof, in aqueous organic solvents in the presence of acids.