that ether substituents α- or β- to an epoxide ring can be tolerated in the ring-opening reaction with β-keto ester dianions. Subsequent acid-promoted cyclisation of the γ-hydroxy β-ketoesters then leads to synthetically useful tetrahydrofurans, as demonstrated by application of this approach to the preparation of (±)-methyl nonactate and (±)-methyl 8-epi-nonactate.
在此给出的一些实施例表明,在与β-
酮酸酯二价阴离子的开环反应中,
环氧化物环的醚取代基α-或β-可以被容许。所述γ-β羟基
酮酯然后导致合成有用的
四氢呋喃的后续酸促进环化,这表现在这种方法的应用的制备(±) -甲基nonactate和(±) -甲基-8-外延-nonactate。