锡催化二羟基丙酮制备乳酸甲酯及其反应过程.

The catalytic behaviors of various tin compounds for the conversion of 1,3-dihydroxyacetone (DHA) to methyl lactate (ML) in methanol, as well as the reaction process, were briefly investigated in a batch reactor. The results indicated that metal cations with strong Lewis acidity, in particular Sn2+ and Sn4+, catalyzed efficiently the conversion of DHA to ML. The performance of tin cation was closely related to its counterpart anions, with the halide anions (Cl- and Br-) acting as promoters. Besides, high temperature favored the yield of methyl lactate when SnCl2 served as a catalyst, yielding the DHA conversion and ML selectivity of 98.2% and of 96.0% respectively at 100℃ Moreover, the evolution of reaction products against time suggested that the conversion of DHA to ML proceeded through a combination of consecutive and parallel reaction steps. Pyruvic aldehyde hemiacetal was the detectable reaction intermediate, whereas ML proved to be final products. [ABSTRACT FROM AUTHOR]