Two chiral spirocyclic dioxinones (S-5 and R-5) useful in teh so-called de Mayo reaction as alternatives to β-diketones (enones) have been synthesized; they not only act as formylacetates (inactive by themselves as enones) but also display remarkable diastereofacial selectivities in photoaddition to alkenes. The sythesis of these dioxinones is described, together with a practicl one-pot synthesis of enantiomerically pure (1S, 4R)-(+)-6-formyl-2-oxabicyclo[3.3.0]oct-6-en-3-one, the key intermediated of prostaglandin synthesis, from the (6S)-spirocyclic dioxinone (S-5).
合成了两种在所谓的de Mayo反应中作为
β-二酮(烯酮)替代品的手性螺环二噁烯酮(S-5和R-5);它们不仅可以作为醛
乙酸酯(自身作为烯酮时不活跃),而且在与烯烃的光加成反应中表现出显著的非对映体面选择性。文中描述了这些二噁烯酮的合成,并提供了一种实用的一锅法合成具有对映体纯度的(1S,4R)-(+)-6-醛-2-氧双环[3.3.0]八-6-烯-3-酮的方法,该化合物是
前列腺素合成的关键中间体,来源于(6S)-螺环二噁烯酮(S-5)。