Synthesis of CH2-Linked α(1,6)-Disaccharide Analogues by α-Selective Radical Coupling C-Glycosylation
摘要:
C-Linked carbohydrate structure, in which the cleavable O-glycosidic linkage is replaced by a carbon unit, is a useful tool for functional analyses of glycoconjugates. We describe a synthetic method for alpha-CH2-linked disaccharide structures, such as Glc(1,6)-Glc, by stereoselective radical-coupling C-glycosylation between a conformationally constrained and stable C1-sp(3) hybridized xanthate donor and a carefully designed acceptor.
Organometallics in organic synthesis. Applications of a new diorganozinc reaction to the synthesis of C-glycosyl compounds with evidence for an oxonium-ion mechanism
作者:Alan P. Kozikowski、Toshiro Konoke、Allen Ritter
DOI:10.1016/s0008-6215(00)90882-6
日期:1987.12
features of a new organozinc-based substitution process [heteroatom-C-(R1,R2)-SPh + R3(2)Zn----heteroatom-C-(R1,R2,R3)], first discovered during a total synthesis of the alkaloid mycotoxin alpha-cyclopiazonic acid, are described. Phenyl thioglycosides were valuable substrates in studying the nature of this reaction process. Since these sulfur compounds are converted into C-glycosylcompounds with some
Reaction of acetylated carbohydrates with trimethylaluminum: concise synthesis of 1,2-O-isopropylidene d-ribofuranose
作者:Jesse D. More、Michael G. Campbell
DOI:10.1016/j.tetlet.2009.03.116
日期:2009.6
Treatment of β-d-ribose tetraacetate with trimethylaluminum gives α-3,5-O-acetyl-1,2-O-isopropylidene-d-ribofuranoside in excellent yield. This reaction allows for efficient and high-yielding installation of the 1,2-isopropylidene acetal (acetonide), which is difficult to prepare using more traditional acid-catalyzed methods. The reaction of trimethylaluminum with other per-acetylated carbohydrates is