691394-91-9Relevant articles and documents
Synthesis of Pentacyclic Framework of Herquline A
Kim, Thomas Taehyung,Lee, Chungwoo,Heo, Seongrok,Lee, Hee-Seung,Han, Sunkyu
supporting information, p. 3882 - 3885 (2021/10/14)
The highly strained bowl-shaped pentacyclic structure of herquline A has rendered it one of the most difficult problems in organic synthesis yet to be solved. The challenges associated with the synthesis of herquline A have been well documented in four Ph.D. dissertations and in multiple reports regarding syntheses of its structurally simpler congeners. Herein, we report the construction of the pentacyclic core of herquline A that contains both N10?C2 and C3?C3′ bonds. The key for success was the development of the tandem aza-Michael addition/enolate capture protocol that set the stage for subsequent palladium catalyzed C3(sp2)?C3′(sp2) coupling reaction. Ensuing oxidative dearomatization of the left aryl ring allowed the formation of the pentacyclic diketone core of herquline A.
Formal Total Synthesis of Diazonamide A by Indole Oxidative Rearrangement
David, Nadège,Pasceri, Raffaele,Kitson, Russell R. A.,Pradal, Alexandre,Moody, Christopher J.
, p. 10867 - 10876 (2016/07/27)
A short formal total synthesis of the marine natural product diazonamide A is described. The route is based on indole oxidative rearrangement, and a number of options were investigated involving migration of tyrosine or oxazole fragments upon oxidation of open chain or macrocyclic precursors. The final route proceeds from 7-bromoindole by sequential palladium-catalysed couplings of an oxazole fragment at C-2, followed by a tyrosine fragment at C-3. With the key 2,3-disubstituted indole readily in hand, formation of a macrocyclic lactam set the stage for the crucial oxidative rearrangement to a 3,3-disubstituted oxindole. Notwithstanding the concomitant formation of the unwanted indoxyl isomer, the synthesis successfully delivered, after deprotection, the key oxindole intermediate, thereby completing a formal total synthesis of diazonamide A.
Synthesis and characterization of the arylomycin lipoglycopeptide antibiotics and the crystallographic analysis of their complex with signal peptidase
Liu, Jian,Luo, Chuanyun,Smith, Peter A.,Chin, Jodie K.,Page, Malcolm G. P.,Paetzel, Mark,Romesberg, Floyd E.
supporting information; experimental part, p. 17869 - 17877 (2012/01/05)
Glycosylation of natural products, including antibiotics, often plays an important role in determining their physical properties and their biological activity, and thus their potential as drug candidates. The arylomycin class of antibiotics inhibits bacte
