“Standardized intermediates” for oligosaccharide synthesis. Precursors of β-linked, interior d-galactopyranose units having chain extension at position 4, or positions 4 and 2
作者:Charles W. Slife、Mina A. Nashed、Laurens Anderson
DOI:10.1016/s0008-6215(00)80851-4
日期:1981.7
derivatives (4 and 14) . Benzoyl, allyl, tert -butyldimethylsilyl, and tetrahydro-2-pyranyl groups, respectively, were incorporated at position 4 by derivatization of the otherwise fully substituted 1-propenyl glycoside 7 , or its precursor 15 . The fully substituted propenyl glycosides (8a-d) were converted into the 1-hydroxy compounds (9a-d) by mercuric ion-catalyzed hydrolysis, and thence directly into
摘要用烯丙基6-O-苄基-3,4-O-异亚丙基-α-d-吡喃半乳糖苷(1)制备了一系列2-O-苯甲酰基-3,6-di-O-苄基-α-d -在第4位带有第二个苯甲酰基(11,17a)或选择性除去的临时保护基(17b-d)的-吡喃半乳糖基卤化物。在一种合成方案中,使用2-丁烯基(巴豆基)进行瞬态保护在2位的2,4-二苯基上,通过选择性酰化2,4-二醇(6)并入2-O-苯甲酰基。在更直接的方案中,在第一步(1→12)中引入了2-O-苯甲酰基。O-3的选择性苄基化是通过α-溴甲苯对3,4-O-二丁基亚锡衍生物(4和14)的作用完成的。分别为苯甲酰基,烯丙基,叔丁基二甲基甲硅烷基和四氢-2-吡喃基 通过否则完全取代的1-丙烯基糖苷7或其前驱物15的衍生作用并入4位上。通过汞离子催化的水解将完全取代的丙烯基糖苷(8a-d)转化为1-羟基化合物(9a-d),然后通过与六甲基磷化三酰胺-四氯化碳反应将其直