甲基吡喃的合成

Synthesis of Methylpyrane

介绍了以多聚甲醛、间戊二烯为原料在四氢呋喃中BF3-乙醚溶液催化作用下进行Diels-Alder反应,合成2-甲基-5,6-二氢-2H吡喃的方法.考察了催化剂和溶剂、反应温度、时间等因素对收率的影响.结果表明,在多聚甲醛用量23 g,间戊二烯91 mL,BF3乙醚溶液1.5～2.0 g.四氢呋喃40～50 g,反应温度140～150℃,时间4 h,常压条件下,收率可达52%.此合成工艺的成功,在一定程度上为顺-3-己烯-1-醇在国内的工业化生产奠定了基础.

Synthesis of methylpyrane from paraformaldehyde and 2,4-pentadiene in tetrahydrofuran in the presence of BF 3-ethyl ether as catalyst by Diels-Alder reaction was presented.The effects of catalysts,solvents,reaction temperature and reaction time on yield of the product were examined.The result showed that the yield of the product could be up to 52% when the reaction was carried out for 4h under reaction conditions as follows:the dosage of paraformaldehyde,2,4-pentadiene,BF 3-ethyl ether and tetrahydrogen were 23 g , 91 mL , 1.5～ 2.0 g and 40～ 50 g respectively at 140～ 150 ℃ under atmospheric pressure.The success of the process provided foundation for commercial production of cis -3-hexene-1-ol.