Diethyl α-alkynyl-α-methoxymalonates (2a—e) were smoothly hydrolyzed and then decarboxylated under alkaline conditions employing 1 N KOH in EtOH to give conjugated allenyl esters (6a—e) in high yields, and similar alkaline treatment of diethyl α-alkynyl-α-acetylaminomalonates (5a, b, d, e) furnished unexpectedly the oxazoles (7a, b, d, e) having three substituent groups in excellent yields.
α-炔基-α-甲氧基
丙二酸二乙酯 (2a-e) 在碱性条件下使用 1
N KOH 的 EtOH 溶液顺利
水解,然后脱羧,以高产率得到共轭
丙二烯基酯 (6a-e),并且对α-炔基-α-
乙酰氨基丙二酸二乙酯(5a、b、d、e)进行类似的碱处理,意外地以优异的产率提供了具有三个取代基的
恶唑(7a、b、d、e)。