Brønsted Acid-Promoted Glycosylations of Disaccharide Glycal Substructures of the Saccharomicins
摘要:
An acid-promoted glycosylation and alkynol cycloisomerization sequence provided direct access to the 2-deoxytrisaccharide corresponding to the fucose-saccharosamine-digitoxose substructure of saccharomicin B. In the course of this work, the absolute stereochemistry of the repeating fucose-saccharosamine disaccharide of saccharomicins was also confirmed.
Fischer Carbene Catalysis of Alkynol Cycloisomerization: Application to the Synthesis of the Altromycin B Disaccharide
作者:BonSuk Koo、Frank E. McDonald
DOI:10.1021/ol070435s
日期:2007.4.1
[reaction: see text] The tungsten-catalyzed cycloisomerization of alkynyl alcohols can be conducted without using photochemistry, using a stable tungsten Fischer carbene as the precatalyst for this transformation. A variety of alkynyl alcohols undergo cycloisomerization under these conditions to provide endocyclic enol ethers of five-, six-, and seven-membered ring sizes. The utility of this method is further
Stereo- and Regioselective Glycosylations to the Bis-<i>C</i>-arylglycoside of Kidamycin
作者:ZhongBo Fei、Frank E. McDonald
DOI:10.1021/ol7014219
日期:2007.8.1
explorations toward the total synthesis of the antitumor anthrapyran natural product kidamycin, the regioselective introduction of aminosugars angolosamine and vancosamine as C-arylglycosides has been accomplished onto hydroxylated anthrapyran aglycones. Specifically, the 9,11-dihydroxylated anthrapyran A undergoes sequential glycosylations with angolosamine synthon B and vancosamine synthon C to regio-
在抗肿瘤蒽吡喃天然产物卡达霉素的全合成探索中,区域选择性地将氨基糖安戈洛胺和万古胺作为C-芳基糖苷引入羟基化蒽吡喃苷元上。具体而言,9,11-二羟基化蒽吡喃 A 与安戈洛胺合成子 B 和万古胺合成子 C 进行连续糖基化,以区域选择性和立体选择性地提供与卡达霉素 C-糖苷模式相对应的双-C-糖苷 D。
Brønsted Acid-Promoted Glycosylations of Disaccharide Glycal Substructures of the Saccharomicins
作者:Bradley R. Balthaser、Frank E. McDonald
DOI:10.1021/ol901923x
日期:2009.11.5
An acid-promoted glycosylation and alkynol cycloisomerization sequence provided direct access to the 2-deoxytrisaccharide corresponding to the fucose-saccharosamine-digitoxose substructure of saccharomicin B. In the course of this work, the absolute stereochemistry of the repeating fucose-saccharosamine disaccharide of saccharomicins was also confirmed.