La cyclocondensation d'un β-D-allo-heptodialdo-1,4 furanosyl-1 uracile issu de l'O-isopropylidene-2,3 uridine et d'un butadiene-1,3 donne un L-allo-α-D -galacto-undecodialdopyranose-1,5furanose-8,11yl 尿嘧啶。Une seconde unite d'un acetamido-2 glupyranose est egalement synthetisee。Ceci constitue unesynthese totale des intermediaires de Suami
The first total synthesis of ipomoeassin F was carried out using a convergent approach that relied upon the use of Schmidt glycosidation technology for the coupling of two suitably protected monosaccharide fragments. After two steps, ring-closing metathesis was used to form the macrocyclic ring, and seven more steps then furnished ipomoeassin F. In vitro inhibitory activity against a four-panel cell line showed low nanomolar inhibitory activity.
Iron-Catalyzed Direct Diazidation for a Broad Range of Olefins
作者:Yong-An Yuan、Deng-Fu Lu、Yun-Rong Chen、Hao Xu
DOI:10.1002/anie.201507550
日期:2016.1.11
synthetically valuable nitrogen‐containing building blocks which are difficult to obtain with alternative methods. Preliminary mechanisticstudies suggest that the reaction may proceed through a new mechanistic pathway in which both Lewisacid activation and iron‐enabled redox‐catalysis are crucial for selective azido‐group transfer.
carbohydrate derived vinylcyclopropanes (VCPs) under electrophilic conditions mediated by chloramine-T and a phase-transfer catalyst. The present work serves as the first example on the studies of the reactivity of carbohydrate VCPs towards the synthesis of densely functionalized oxepane analogues. The work elaborates on a reasonable mechanism for the product formation and our observations on the diastereoselectivity
Selective formation of C-2 azidodeoxy-d-glucose derivatives from d-glucal precursors using the azidonitration reaction
作者:Peter H. Seeberger、Susanne Roehrig、Peter Schell、Yuan Wang、William J. Christ
DOI:10.1016/s0008-6215(00)00111-7
日期:2000.8
groups, were subjected to the azidonitration reaction to furnish the corresponding C-2 azidodeoxy-D-glucoses. 4,6-O-Isopropylidene-3-O-triisopropylsilyl-D-arabino-hex-1-enit ol afforded 2-azido-2-deoxy-4,6-O-isopropylidene-3-O-triisopropylsilyl-D-gluco pyranosyl nitrate and its D-manno isomer in a 20:1 ratio. These findings allow the azidonitration reaction to be now used for the preparation of a variety
NFSI mediated C3-ether oxidation of glycals for the synthesis of hex-3-enuloses
作者:Pradip Das、Rima Thakur
DOI:10.1016/j.carres.2024.109032
日期:2024.2
constitute a vital carbohydrate synthetic intermediate that provide access to wide range of chiral molecules through diverse derivatizations. Herein we report synthesis of these fascinating scaffolds by oxidation of C3-ether protections on glycals in presence of N-fluorobenzenesulfonimide (NFSI) under Cu(I) catalysed conditions. Benzyl, methyl and silyl ethers have been efficiently oxidized to the carbonyl