Oxidative formylation and chloromethylation in Vilsmeier reactions of O- and S-heterocyclic ketones
作者:Paul R. Giles、Charles M. Marson
DOI:10.1016/s0040-4020(01)86387-0
日期:1991.1
The action of DMF-POCl3 at 20 °C on tetrahydro-4H-pyran-4-one, tetrahydro-4H-thiopyran-4-one, chroman-4-one, and thiochroman-4-one affords the corresponding β-chlorovinylaldehydes. However, with excess DMF-POCl3 at 100 °C, chroman-4-one affords 3-(chloromethyl)chromone, and thiochromanone gives 3-formylthiochromone. Mechanistic rationalisations are provided.
DMF-POCl 3在20°C下对四氢4 H-
吡喃-4-酮,四氢4 H-
硫代
吡喃-4-酮,苯并
吡喃-4-酮和
硫代苯并
吡喃-4-酮的作用提供了相应的β -
氯乙烯基醛。但是,在100°C下使用过量的
DMF-POCl 3时,
苯并二氢吡喃-4-酮可制得3-(
氯甲基)苯并二氢
吡喃酮,而
硫代苯并二氢
吡喃酮可制得3-甲酰基
硫代
色酮。提供了机械合理性。