De Novo Asymmetric Synthesis of Anthrax Tetrasaccharide and Related Tetrasaccharide
作者:Haibing Guo、George A. O’Doherty
DOI:10.1021/jo800691v
日期:2008.7.1
A denovoasymmetric approach to the natural product anthraxtetrasaccharide 1 and an analogue 2 with an anomeric hexyl azide group has been developed from acetylfuran. The construction of the tetrasaccharide was achieved by a traditional [3 + 1] glycosylation strategy. An iterative diastereoselective palladium-catalyzedglycosylation, Luche reduction, diastereoselective dihydroxylation, and regioselective
Synthesis of the Hexasaccharide Fragment of Landomycin A Using a Mild, Reagent-Controlled Approach
作者:Subbarao Yalamanchili、Dina Lloyd、Clay S. Bennett
DOI:10.1021/acs.orglett.9b01118
日期:2019.5.17
The synthesis of the hexasaccharide fragment of landomycin A is reported. Using p-toluenesulfonyl chloride mediated dehydrative glycosylation, we constructed the deoxy-sugar linkages in a stereoselective fashion without the need for temporary prosthetic groups to control selectivity. Through this approach, the hexasaccharide was obtained in 28 steps and 8.9% overall yield, which is an order of magnitude
Reagent Controlled Direct Dehydrative Glycosylation with 2-Deoxy Sugars: Construction of the Saquayamycin Z Pentasaccharide
作者:J. Colin Mizia、Clay S. Bennett
DOI:10.1021/acs.orglett.9b02056
日期:2019.8.2
The first synthesis of the pentasaccharide fragment of the angucycline antibiotic saquayamycin Z is described. By using our sulfonyl chloride mediated reagent controlled dehydrative glycosylation, we are able to assemble the glycosidic linkages with high levels of anomeric selectivity. The total synthesis was completed in 25 total steps, and in 2.5% overall yield with a longest linear sequence of 15
New Chiral Pool Approach to Anthracyclinones. The Stereoselective Synthesis of Idarubicinone
作者:Osman Achmatowicz、Barbara Szechner
DOI:10.1021/jo026354l
日期:2003.3.1
present work, a new chiral pool approach has been developed for the synthesis of anthracyclinones. Thus, enone 8, readily available from l-rhamnose, has been converted via addition of 2,5-dimethoxybenzyllithium to the carbonyl group and a series of six reactions into a suitably protected aldehyde 21. The SnCl(4)-promoted stereospecific cyclization of the latter afforded enantiopure key intermediate 22
Synthese eines Isomeren des Pentadesoxydisaccharids vom CB‐Typ in Anthracyclin‐Glycosiden
作者:Joachim Thiem、Monika Holst、Jens Schwentner
DOI:10.1002/cber.19801131107
日期:1980.11
α-Benzylglycosid 8 der 4-O-Acetyl-2,3,6-tridesoxy-L-erythro-hex-2-enopyranose hergestellt. Nach Verseifung und Mesylierung zu 10 erfolgt über eine Inversion an C-4 dieDarstellungdes epimeren L-threo-Glycosids 12. Dessen Epoxidierung führt zu einem 5:1-Gemisch der 2,3-Anhydro-L-talo- 13 sowie der -L-gulo-Verbindung 16. Die Bortrifluorid-katalysierte Kondensation von 7 mit 13 gibt das Disaccharid 19, bei dessen
4 O-乙酰基-2,3,6-三苯氧基-L-赤型-己基-2-烯吡喃糖的α-苄基糖苷8是由二乙酰基-L-鼠李产生的(7)。皂化并甲磺酰化为10后,差向异构L-苏糖苷12以C-4倒位表示。它的环氧化作用会导致2,3,anhydro -L- talo - 13和-L - gulo-化合物16的5:1混合物。三氟化硼催化的7与13的缩合反应生成二糖19,其与碘化锂的反应令人惊讶地仅获得了3-碘代醇衍生物20。最终的氢化导致21的形成,它与蒽环类抗生素dihydrocinerubin A(3)和dihydroaclacinomycin A(4)中的C-B型戊二氧基二糖同分异构。