The photochemical [2 + 2] cycloaddition of chiral 3-chloro and 3-fluoro-5-hydroxymethyl-2(5H)-furanone to ethylene and acetylene has been studied. The effect of the halogen atom on the chemical yield and facial diastereoselectivity of the cycloaddition process has been evaluated. From the major anti cycloadducts, practical syntheses of several purine cyclobutane and cyclobutene-fused nucleosides containing
研究了手性3-
氯和3-
氟-
5-羟甲基-2(5 H)-
呋喃酮向
乙烯和
乙炔的光
化学[2 + 2]环加成反应。已经评估了卤素原子对环加成过程的
化学收率和面部非对映选择性的影响。从主要的抗环加合物开始,已经开发了几种
嘌呤环丁烷和含卤原子的
环丁烯稠合核苷的实用合成方法。已经评估了新的核苷类似物的抗HIV活性。