[reaction: see text] Photolysis at 254 nm of neat (no solvent) unsymmetrical diacyl peroxides derived from cyclopropane carboxylic acids and l-aspartic acid generates protected beta-cyclopropylalanines in reasonable yields. Orthogonally protected 3-(trans-2-aminocyclopropyl)alanine (21), a key constituent of the antitumor agent belactosin A, as well as protected hypoglycin A (26), a causative agent
[反应:参见正文] 254纳米(无溶剂)衍生自
环丙烷羧酸和l-
天冬氨酸的纯净(不溶剂)不对称二酰基过氧化物的光解以合理的收率生成了受保护的β-环丙基丙
氨酸。通过这种方法,可以合成
抗肿瘤药物贝洛糖素A的关键成分的正交保护的3-(反式-2-
氨基环丙基)丙
氨酸(21)和牙买加呕吐病的病原体受保护的次糖苷A(26)。中间取代的环丙基自由基的偶联主要在保留构型的情况下进行(dr>或= 95:5)。