HYDROLYSIS OF THE GLCNAC OXAZOLINE - DEAMIDATION AND ACYL REARRANGEMENT
HYDROLYSIS OF THE GLCNAC OXAZOLINE - DEAMIDATION AND ACYL REARRANGEMENT
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DOI：
10.1016/0008-6215(95)00222-f
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发表时间：
1995-11-07
影响因子：
3.1
通讯作者：
DAVIS, JT
中科院分区：
文献类型：
--
作者：
JHA, R;DAVIS, JT
2-乙酰氨基-1,3,4,6-四-O-乙酰基-α-D-吡喃葡萄糖的特异性脱酰胺作用是通过对甲苯磺酸促进的 2-甲基-(3,4,6-三-O-乙酰基-1,2-二脱氧-α-D-吡喃葡萄糖)-[2,1-d]-2-恶唑啉 2 的水解来实现的，从而定量形成1,3,4,6-四-O-乙酰基-2-氨基-2-脱氧-α-D-吡喃葡萄糖对甲苯磺酸盐(5d)。该两步程序提供了可以容易地酰化以得到新型糖缀合物的氨基糖。或者，氨基甲苯磺酸酯5d的碱催化O-1→N-2酰基重排得到2-乙酰胺基-3,4,6-三-O-乙酰基-2-脱氧-D-吡喃葡萄糖4，为α和β端基异构体的9:1混合物。因此，GlcNAc恶唑啉2的水解产生作为动力学产物的氨基酯5和作为热力学产物的酰胺基醇4。
The specific deamidation of 2-acetamido-1,3,4,6-tetra-O-acetyl-alpha-D-glucopyranose is achieved by p-toluenesulfonic acid-promoted hydrolysis of 2-methyl-(3,4,6-tri-O-acetyl-1,2-dideoxy-alpha-D-glucopyrano)-[2,1-d]-2-oxazoline 2 to give quantitative formation of the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-alpha-D-glucopyranose p-toluenesulfonate (5d). This two-step procedure provides an amino sugar which may be readily acylated to give novel glycoconjugates. Alternatively, base-catalyzed O-1 --> N-2 acyl rearrangement of the amino tosylate 5d gives the 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-D-glucopyranose 4 as a 9:1 mixture of alpha and beta anomers. Thus, hydrolysis of GlcNAc oxazoline 2 gives the amino-ester 5 as the kinetic product and the amido-alcohol 4 as the thermodynamic product.