selective acetylation of racemic 1-[6-(1-hydroxyethyl)-pyridin-2-yl]ethanone rac-2 to yield alcohol (S)-2 and acetate (R)-3. Acetylation of a diastereomeric mixture of racemic and meso-2,6-bis(1-hydroxy-ethyl)pyridine, rac/meso-4, with the most selective Novozym 435 lipase in vinyl acetate resulted in a mixture of enantiopure diol (S,S)-4, monoacetate (R,S)-5 and diacetate (R,R)-6. Hydrolysis of the
几个
脂肪酶中测试的外消旋-
吡啶-2-基-6-(1-羟乙基)]乙酮对映异构选择性乙酰化1-外消旋- 2,得到醇(小号) - 2和
乙酸([R ) - 3。外消旋和内消旋-2,6-双(1-羟基-乙基)
吡啶的非对映异构体混合物rac / meso - 4与
乙酸乙烯酯中选择性最高的Novozym 435
脂肪酶的乙酰化反应产生对映体纯二醇(S,小号) - 4,单
乙酸酯(- [R ,小号) - 5和二
乙酸盐(ř,R)-6。外消旋和内消旋-2,6-双(1-乙酰氧基乙基)
吡啶rac / meso - 6的混合物通过相同的酶
水解,得到二醇(R,R)-4,单
乙酸(S,R)-的纯对映体5和二
乙酸(S,S)-6。使用其他
化学和酶促步骤,醇(R)-2,
乙酸酯(S)-3,(S,S)-和(R,[R)-monoacetates(小号,小号) - 5和(- [R ,- [R )- 5,内消旋- 4及其
乙酸酯内消旋- 6还制备和表征。