β-d-gluco- and β-d-mannopyranosyl)-pyridinium salts were obtained and their structures were determined by 2D 1H NMR spectroscopy. The compounds obtained were treated with a methanolic solution of sodium methylate. The β-anomer of the d-gluco derivative cyclizes via Brigl's anhydride but the α anomer is competitively transformed according to the SN2 and SN1 mechanisms. The β-d-manno derivative does not
获得了N-(2,3,4,6-四-O-乙酰基-α - d-
葡萄糖-,β- d-
葡萄糖和β- d-甘露
吡喃糖基)-
吡啶鎓盐,并通过2D 1确定了它们的结构。1 H NMR光谱。用
甲醇钠的
甲醇溶液处理获得的化合物。所述的β端基异构体d -gluco衍
生物环化经由Brigl的酐但α端基异构体是根据在S竞争转化Ñ 2和S Ñ 1点的机制。β- d-
甘露聚糖衍
生物在使用的条件下不会环化。通过比较所研究反应的定性和定量结果,可以估算C-1和C-2构型对环化过程的影响。所有产品混合物均通过毛细管气相色谱法(CGC)进行了详尽的O-乙酰化衍
生物的分离,并通过与真实材料的共注射来鉴定其成分。