The effect of temperature on the Pictet-Spengler reaction of Nb-hydroxytryptamines (1) and cysteinals (2) has been examined. The optically active nitrones (3), obtained from 1 and 2, gave the corresponding Nb-hydroxy-β-carbolines (4α and 4β) exclusively at -78°C in the presence of an excess of trifluoroacetic acid. The mechanism is discussed in relation to the stereochemistry.
对温度对Nb-羟基
色胺(1)和半胱
氨醇(2)的Pictet-Spengler反应的影响进行了研究。从1和2中获得的具有光学活性的硝
酮(3)仅在-78°C且存在过量
三氟乙酸的情况下产生相应的Nb-羟基-β-咔啉(4α和4β)。结合立体
化学讨论了反应机理。