and 3-hydroxyl groups are cis) were exclusively obtained in high yields. On the other hand, a nearly equimolecular amount of the cis and trans isomers was obtained from the reaction of 2-formyl derivatives under the same conditions.
3-烷基-3-羟基-5-硝基-
2,3-二氢-2-苯并呋喃羧酸乙酯是通过2-酰基-4-
硝基苯氧基
乙酸乙酯与
氢氧化钾在干燥
二恶烷中的反应获得的。顺式和反式异构体在 C-2 和 C-3 立体
化学方面的相对比例根据酰基的结构而变化。当酰基为乙酰基、丙酰基或异丁酰基时,顺式异构体(2-烷氧基羰基和3-羟基为顺式)只能以高产率获得。另一方面,在相同条件下从 2-甲酰基衍
生物的反应中获得了几乎等摩尔量的顺式和反式异构体。