The prochiral recognition between enantiotopic carbonyl groups in the reaction of 3-substituted glutaric and 3,4-disubstituted adipic anhydrides with anions of Evansâ oxazolidinones has been investigated. Each of the Ï-symmetric anhydrides provided a diastereoisomeric mixture of half-acids which were separated either by fractional crystallization or by column chromatography of their esters. The diastereoselectivity of the desymmetrization reaction is dependent on the substituents present in the anhydrides.
研究了Evans的
噁唑烷酮阴离子与3-取代
戊二酸酐及3,4-二取代
己二酸酐反应中对映异位羰基之间的前手性识别。每个σ对称酸酐提供了半酸的非对映异构体混合物,它们通过分步结晶或其酯的柱色谱法分离。这种脱对称反应的非对映选择性取决于酸酐中存在的取代基。