When NO- 3 is electrochemically oxidized in the presence of a variety of terminal and 1,2-disubstituted olefins 1 in a mixed solvent system (MeCN: H2O: Et2O = 10: 2:1), a radical NO3 is generated from NO- 3 and nitrate esters 3 are formed by a new coupling reaction of the olefin with the radical. The products 3 can be further transformed into the corresponding alcohols 4 and alkyl iodides 5. Under the same reaction conditions, 1,1-di- and 1,1,2-trisubstituted olefins 6 do not give nitrate esters but afford oxazoline derivatives 7. (1S,5S)-(-)-ß-Pinene (13) is diastereoselectively transformed into (1S,2R,5S)-(-)-myrtanol (14) by this technique.
当在混合溶剂系统(MeCN:
H2O:Et2O = 10:2:1)中,NO-3在存在多种末端和1,2-二取代烯烃1的情况下进行电
化学氧化时,NO-3会生成自由基
NO3,并且通过烯烃与该自由基的新偶联反应形成
硝酸酯3。产物3可以进一步转化为相应的醇4和烷基
碘5。在相同的反应条件下,1,1-二取代和1,1,2-三取代烯烃6不产生
硝酸酯,而是生成
恶唑啉衍
生物7。通过这种技术,(1S,5S)-
(-)-β-蒎烯(13)可以立体选择性地转化为(1S,2R,5S)-(-)-
杨梅醇(14)。