Comparative study of conformational effects on stereoselective lipase catalysed acetylation of sec hydroxy groups in diastereomeric 14-membered lactones and their acyclic analogs
作者:Edina Ljubović、Vitomir Šunjić
DOI:10.1016/s0040-4039(00)01634-8
日期:2000.11
15, catalysed by seven microbial lipases in n-heptane afforded the C(7)-O-acetyl derivative 17 with up to 99% diastereomeric excess (d.e.), whereas acetylation of their acyclic analogs 10, 11 afforded C(5)-O-acetyl derivative 13 with up to 93% d.e. Six lipases, from Pseudomonas cepacia (PCL), Pseudomonas fluorescens (PFL), Geotrichum candidum (GCL), Candida cylindracea (CCL) and Pseudomonas cepacia
的立体选择性乙酰化秒在非对映体的羟基(1:1)的大环内酯的混合物14,15,由7的微生物脂肪酶中催化Ñ庚烷,得到C(7) - ø -乙酰基衍生物17与高达99%的非对映体过量(DE),而其无环类似物的乙酰化10,11,得到C(5) - ø -乙酰基衍生物13与高达93%的德六脂肪酶,来自洋葱假单胞菌(PCL),荧光假单胞菌(PFL),白地霉(GCL ),念珠菌(CCL)和洋葱假单胞菌固定在陶瓷(PS-C)上,主要是乙酰化环状非对映异构体(3 S,7 S)-15至(3 S,7 S)-17;仅南极假丝酵母-B(CAL-B)脂肪酶主要是(3 S,7 R)-14至(3 S,7 R)-16乙酰化。与无环类似物10,11相同的一组的脂肪酶均显示出不同的非对映选择性偏压; CAL-B,GCL和CCL主要为酰化物(1 S,5 S)-11至(1 S,5 S)-13,而PCL,PS-C,PFL和PSL主要酰化(1