Liav A, Goren M B
Carbohydr Res. 1984 Jul 1;129:121-9. doi: 10.1016/0008-6215(84)85304-5.
Selective triflation of 4,6:4',6'-di-O-benzylidene-alpha,alpha-trehalose gave 4,6:4',6'-di-O-benzylidene-2,2'-di-O-triflyl-alpha,alpha-trehalose , the structure of which was confirmed by the 1H-n.m.r. spectrum of its 3,3'-di-O-acetyl derivative (4). Treatment of 4 with sodium nitrite in hexamethylphosphoric triamide, followed by benzylation, afforded 2,3,2',3'-tetra-O-benzyl-4,6:4',6'-di-O-benzylidene-(alpha-D-mannopyrano syl alpha-D-mannopyranoside (7). Removal of the two benzylidene groups from 7, and selective tosylation of the product, gave a mixture of the 6,6'-ditosylate (11) and the 6-monotosylate (12), which were separated by chromatography. Treatment of 11 with potassium corynomycolate or potassium mycolate afforded the corresponding 6,6'-diesters, 14 and 15, respectively. Treatment of the monotosylate 12 with potassium corynomycolate gave the 6-monoester 18. Catalytic hydrogenolysis of 14, 15, and 18 gave the respective cord-factor analogs.
4,6:4',6'-二-O-亚苄基-α,α-海藻糖的选择性三氟甲磺酸酯化反应得到了4,6:4',6'-二-O-亚苄基-2,2'-二-O-三氟甲磺酰基-α,α-海藻糖，其结构通过其3,3'-二-O-乙酰基衍生物（4）的1H-核磁共振谱得以确认。在六甲基磷酸三酰胺中用亚硝酸钠处理4，然后进行苄基化反应，得到2,3,2',3'-四-O-苄基-4,6:4',6'-二-O-亚苄基-(α-D-甘露吡喃糖基α-D-甘露吡喃糖苷（7）。从7中除去两个亚苄基基团，并对产物进行选择性甲苯磺酰化反应，得到6,6'-二对甲苯磺酸酯（11）和6-单对甲苯磺酸酯（12）的混合物，通过柱色谱法将它们分离。用棒状杆菌酸钾或霉菌酸钾处理11，分别得到相应的6,6'-二酯，即14和15。用棒状杆菌酸钾处理单对甲苯磺酸酯12得到6-单酯18。对14、15和18进行催化氢解反应得到各自的类索状因子类似物。
