Uncatalyzed solventless Diels–Alder reaction of 2-amino-3-nitroacrylate: synthesis of new epimeric 2-amino-3-nitro-norbornene- and norbornane-2-carboxylic acids
affords the ethyl 2-t-butoxycarbonylamino-3-endo-nitro-bicyclo[2.2.1]hept-5-ene-2-exo-carboxylate: a new constrained carbocyclic amino acid. Catalytic hydrogenation of this cycloadduct gave the corresponding reduced norbornane derivative. A preliminary investigation into the chemistry of these two amino acids was performed. In particular, the epimerization to their corresponding 3-exo-nitro compounds
在纯净条件下,环戊二烯与(Z)-2 - N -Boc-氨基-3-硝基丙烯酸乙酯之间的高度非对映选择性Diels-Alder反应得到乙基2 - t-丁氧基羰基氨基-3-内-硝基-双环[2.2.1] hept-5-ene-2- exo-羧酸盐:一种新的受限制的碳环氨基酸。该环加合物的催化氢化得到相应的还原的降冰片烷衍生物。对这两种氨基酸的化学性质进行了初步研究。特别地,研究了通过用酸和碱处理两者向其相应的3- exo-硝基化合物的差向异构化。从这项研究中,有关内膜/外膜的有价值的信息获得了在C-3碳原子上的反应以及不同立体异构体的稳定性的方法。稳定性与环中是否存在双键以及取代模式密切相关。最后,已经进行了氨基酸功能的脱保护。