Bocdene and mocdene derivatives of catechols and catecholamines

[GRAPHICS] Catechols react chemoselectively, in the presence of either alcohols, 1,2-d iols, or simple phenols, with tert-butyl propynoate and with methyl propyno ate to give 2-Boc-ethylidene (Bocdene) and 2-Moc-ethylidene (Mocdene) aceta ls, respectively, in 96-100% yields within 30 min at room temperature, prov ided that 150 mol % of DMAP is added. Cleavage of these acetals with pyrrol idine readily takes place (at room temperature!) in 95-100% yields, By taki ng advantage of the features of Bocdene acetals, novel catecholamine-relate d phosphate mimetics have been prepared.