作者:Irina Kempter、Andreas Groß、Jens Hartung
DOI:10.1016/j.tet.2012.08.083
日期:2012.12
α-position to the acceptor group. In intramolecular competition experiments, alkoxyl radicals add similarly fast to a cyano-substituted double bond than to a terminal alkene, but by a factor >25 faster to an enol ether. The nucleophilic component of alkoxyl radical reactivity opens an interesting new access to tetrahydrofuryl amino acids via C,O-cyclization, as shown by synthesis of a N,O-protected 5-p
烷氧基基团选择性地在氰基和甲氧基羰基取代的碳-碳双键上添加5- exo - trig,得到α-受体-α-四氢呋喃基-2-甲基。通过Bu 3 SnD捕集环化的自由基,可在受体基团的α位上提供特定位氘标记的产物。在分子内竞争实验中,烷氧基基团向氰基取代的双键的添加速度比向末端烯烃的速度快,但向烯醇醚的添加速度快25倍。烷氧基自由基反应性的亲核组分通过C,O-环化开创了一种有趣的新途径,使四氢呋喃基氨基酸进入N,O-保护的5-苯基四氢呋喃基-2-甲基甘氨酸的合成。