反应详情

In 2 mL of DMF were suspended 500 mg (2.2 mmol) of N-acetylmannosamine. Vinylacetate (1 mL, 5 equivalent) and 160 mg of subtilisin mutant 8399 [Zhong et al., J. Am. Chem. Soc., 113:683 (1991)] were then added and the suspension was stirred vigorously at room temperature. The reaction progress was monitored by TLC with ethyl acetate/methanol (2/1). After 5 hours when the formation of the di-acetylated derivatives began, the reaction was stopped by evaporating the vinylacetate and DMF. Methanol was then added to dissolve the sugar. After the enzyme and salt were filtered off, the filtrate was concentrated. The residual syrup was chromatographed on a silica gel, with ethyl acetate/methanol (10/1) to give 6-O-Acetyl N-acetylmannosamine (92 percent) as α/β mixture (3:1) based on the NMR spectrum.

1. customby evaporating the vinylacetate and DMF
2. additionMethanol was then added
3. dissolutionto dissolve the sugar
4. filtrationAfter the enzyme and salt were filtered off
5. concentrationthe filtrate was concentrated
6. customThe residual syrup was chromatographed on a silica gel, with ethyl acetate/methanol (10/1)