in the 1H-NMR spectra was indicative of these structures. α-Face addition took place in the case of morphinan dienes with opened ring E, and a by-product was formed due to the SE reaction of PTAD with the adducts. The structure of these derivatives was confirmed by means of NMR spectroscopic methods. The retro Diels-Alder (rDA) reaction of the adducts 4a and 4b readily took place in polar-aprotic solvents
各种
吗啡喃二烯的反应,例如
蒂巴因(1a),N-脱甲基-N-甲酰基
蒂巴因(1b),6-脱甲氧基
蒂巴因(1c),β-二氢
蒂巴因(2a),4-乙酰氧基-β-二氢
蒂巴因(2b),7-具有4-苯基-4 H -
1,2,4-三唑啉-3,5-二酮(
PTAD)的
氯-6-脱甲氧基
蒂巴因(3a)和7-
溴-6-脱甲氧基
蒂巴因(3b)产生了新的Diels-Alder (
DA)加合物。1a,1b和1c与
PTAD的
DA反应导致二烯体在二烯单元的β面攻击产物。在W耦合(4 Ĵ 5β,181 H-NMR光谱中的1)表明这些结构。α-FACE除了发生在与开环E
吗啡喃二烯的情况下,和一个副产物形成,由于在S È
PTAD与加合物反应。这些衍
生物的结构通过NMR光谱法确认。加成物4a和4b的逆Diels-Alder(r
DA)反应易于在极性低的非质子传递溶剂中,在具有低亲核特性的碱存在下进行。