Rearrangement of 4-acetoxy-2H-1,4-benzoxazin-3(4H)-one.
作者:YUICHI HASHIMOTO、TAKAYOSHI ISHIZAKI、KOICHI SHUDO、TOSHIHIKO OKAMOTO
DOI:10.1248/cpb.31.3891
日期:——
4-Acetoxy-2H-1, 4-benzoxazin-3 (4H)-one (3) undergoes rearrangement or nucleophilic attack to give 2-, 5-, 6-, and 7-substituted derivatives of the benzoxazinone according to the reaction conditions. The formation of 5- and 7-substituted products was interpreted in terms of nucleophilic attack on the cation (14) formed by the heterolysis of the N-O bond of 3. For the formation of 6-substituted derivatives of the benzoxazinone, participation of the oxygen atom at position 1 of the benzoxazinone (that is, formation of an oxonium ion, 18) is important. A possible mechanism for the formation of 2-substituted products also involves an oxonium ion (19). These novel aspects of acetoxybenzoxazinone chemistry may contribute to an understanding of the mechanism of the actions of the prohibitins in cereal plants.
4-乙酰氧基-2H-1, 4-苯并恶嗪-3 (4H)-酮(3)根据反应条件进行重排或亲核攻击,得到苯并恶嗪酮的2-、5-、6-和7-取代衍生物。 5-和7-取代产物的形成被解释为对由3的N-O键杂解形成的阳离子(14)的亲核攻击。对于苯并恶嗪酮的6-取代衍生物的形成,氧的参与苯并恶嗪酮 1 位原子(即形成氧鎓离子 18)很重要。形成 2-取代产物的一个可能机制还涉及氧鎓离子 (19)。乙酰氧基苯并嗪酮化学的这些新颖方面可能有助于理解谷类植物中抑制素的作用机制。