A Novel Synthesis of 4-Methyl-1,3-Dioxolane-4-Carbaldehydes by Epoxidation of 5-Methyl-4<i>H</i>-1,3-Dioxins and Acid-Catalyzed Rearrangement
作者:Carsten Wattenbach、Martin Maurer、Herbert Frauenrath
DOI:10.1055/s-1999-2601
日期:1999.3
A straightforward procedure for the synthesis of 4-methyl-1,3-dioxolane-4-carbaldehydes 2 is reported. The new procedure involves m-CPBA oxidation of 5-methyl-4H-1,3-dioxins 5 in dichloromethane to give (4-(m-chlorobenzoyloxy)-5-hydroxy-5-methyl-1,3-dioxanes 6 and acid-catalyzed rearrangement of 6 to carbaldehydes 2. By using commercially available m-CPBA the oxidation and rearrangement can be carried out as a one-pot reaction. The procedure is also applicable to 4H-1,3-dioxins. Oxidation of 5 in methanol led to 4-methoxy-5-hydroxy-1,3-dioxanes 7, which did not undergo acid-catalyzed rearrangement.
报道了合成 4-甲基-1,3-二氧戊环-4-甲醛 2 的简单程序。新方法涉及在二氯甲烷中对 5-甲基-4H-1,3-二恶英 5 进行 m-CPBA 氧化,得到 (4-(间氯苯甲酰氧基)-5-羟基-5-甲基-1,3-二恶烷 6 和酸6 催化重排为甲醛 2. 通过使用市售的 m-CPBA,氧化和重排可作为一锅反应进行。该过程也适用于 4H-1,3-二恶英在甲醇中的氧化。产生4-甲氧基-5-羟基-1,3-二恶烷7,其不经历酸催化重排。