331456-83-8Relevant articles and documents
Synthesis of Cardiotonic Steroids Oleandrigenin and Rhodexin B
Fejedelem, Zachary,Carney, Nolan,Nagorny, Pavel
, p. 10249 - 10262 (2021/07/31)
This article describes a concise synthesis of cardiotonic steroids oleandrigenin (7) and its subsequent elaboration into the natural product rhodexin B (2) from the readily available intermediate (8) that could be derived from the commercially available steroids testosterone or DHEA via three-step sequences. These studies feature an expedient installation of the β16-oxidation based on β14-hydroxyl-directed epoxidation and subsequent epoxide rearrangement. The following singlet oxygen oxidation of the C17 furan moiety provides access to oleandrigenin (7) in 12 steps (LLS) and a 3.1% overall yield from 8. The synthetic oleandrigenin (7) was successfully glycosylated with l-rhamnopyranoside-based donor 28 using a Pd(II)-catalyst, and the subsequent deprotection under acidic conditions provided cytotoxic natural product rhodexin B (2) in a 66% yield (two steps).
Synthesis of the Salmonella type E(1) core trisaccharide as a probe for the generality of 1-(benzenesulfinyl)piperidine/triflic anhydride combination for glycosidic bond formation from thioglycosides.
Crich, David,Li, Hongmei
, p. 4640 - 4646 (2007/10/03)
A synthesis of a chromogenic glycoside of the Salmonella anatum group E(1) core trisaccharide is presented in which all three glycosidic bonds, a 1,2-cis-equatorial, a 1,2-trans-axial, and a 1,2-trans-equatorial linkage representing three of the four main classes of glycosidic bond, are formed with thioglycoside donors activated under a single set of conditions by the combination of 1-(benzenesulfinyl)piperidine and trifluoromethanesulfonic anhydride. 2,3-O-Carbonyl- and 2,3-O-isopropylidene-alpha-L-rhamnopyranosyl thioglycosides are found to be highly alpha-selective rhamnosyl donors under these conditions.
Total synthesis of apoptolidin: Part 1. Retrosynthetic analysis and construction of building blocks
Nicolaou,Li, Yiwei,Fylaktakidou, Konstantina C.,Mitchell, Helen J.,Wei, Heng-Xu,Weyershausen, Bernd
, p. 3849 - 3854 (2007/10/03)
No less than 30 stereogenic elements, a highly unsaturated 20-membered macrocyclic system, four carbohydrate units, and unique biological activity, make the natural occurring apoptolidin (1) a challenging synthetic target. The retrosynthetic analysis reve