A Convenient Procedure for he Synthesis o 2,3,4,6-Tetra-O-benzyl-D-gluconolactam andD-Nojirilactam
作者:Roland Hoos、Andrew B. Naughton、Andrea Vasella
DOI:10.1002/hlca.19930760435
日期:1993.6.30
6. Cyclization of 4 to the very slowly equilibrating 5 and 6 was completed by treatment with AcOH in CHCl3. The configuration of the hydroxy-lactams was assigned on the basis of NOEs. Reduction (Et3SiH/BF3 · Et2O) of the hydroxy-lactams either individually or as a mixture led to 2,3,4,6-tetra-O-benzyl-D-gluconolactam (7). The procedure, based upon modifications of a patent, does not require chromatography;
对2,3,4,5-四-O-苄基-D-葡萄糖(1)进行剧烈氧化,然后进行氨解,得到结晶的酰胺3,将其氧化(DMSO /吡啶·SO 3),得到氧代酰胺4和羟基内酰胺5和6。通过在CHCl 3中用AcOH处理,完成4到非常缓慢平衡的5和6的环化。羟基-内酰胺的构型基于NOE确定。还原(Et 3 SiH / BF 3 ·Et 2O)的羟基-内酰胺单独或作为混合物产生2,3,4,6-四-O-苄基-D-葡糖内酰胺(7)。基于专利的修改,该程序不需要色谱法;的总产率7从1是43%。7的加氢水解得到D-去甲基内酰胺(8); 苄基化导致已知的五苄基-D -nojirilactam(9)和不饱和内酰胺10。