Iodosobenzene diacetate-Iodine and IBX-Iodine: Reagent systems for the synthesis of diastereomerically enriched 2-deoxy-2-iodoglycosyl acetates and 2-deoxy-2-iodoglycosyl ortho-iodobenzoates from protected glycals
作者:Puli Saidhareddy、Sama Ajay、Arun K. Shaw
DOI:10.1016/j.tet.2017.06.001
日期:2017.7
stereoselective synthesis of trans-2-deoxy-2-iodoglycosylacetates and O-iodobenzoates respectively from differently protectedglycals have been developed. They are compatible with a variety of protecting groups and various functional groups at 2C-position. Hexose-3,2-enolone 8 is obtained directly from 2-acetoxy glycal 5 by method A. An application to modified method B has been shown by synthesis of a diastereomerically
Stereoselective synthesis of UDP-2-(2-ketopropyl)galactose aided by di-tert-butylsilylene protecting group
作者:Yasuharu Sakamoto、Tsuyoshi Ohta、Yukishige Ito
DOI:10.1007/s10719-015-9581-y
日期:2015.10
UDP-2-(2-ketopropyl)galactose (1) has been utilized as a valuable probe for profiling proteins modified by O-GlcNAc. In this work, we developed a protocol for efficient synthesis of 1. Thus, 2-methallylgalactose derivative 11, a synthetic intermediate for the compound 1, was prepared by stereoselective iodination and methallylation at C-2 position, through exploitation of 4,6-O-di-tert-butylsilylene protecting group.
A new sulfonium-salt-based iodine(I) reagent system for the vicinal functionalisation of glycals and enol ethers has been developed. The unprecedented iodine(I) complex, Me3SI(OAc)2, generated in situ from Me3SI and PhI(OAc)2, effectively promoted the one-pot iodocarboxylation using carboxylic acids, and iodoazidation using NaN3 or TMSN3 (trimethylsilyl azide). The scope and generality of the new reagent
Improved synthesis of UDP-2-(2-ketopropyl)galactose and a first synthesis of UDP-2-(2-ketopropyl)glucose for the site-specific linking of biomolecules via modified glycan residues using glycosyltransferases
作者:Andrés E. Dulcey、Pradman K. Qasba、Jeffrey Lamb、Gary L. Griffiths
DOI:10.1016/j.tet.2011.01.081
日期:2011.3
The potential of wild-type and mutant glycosyltransferases to produce glycoconjugates carrying sugar moieties with chemical handles has made it possible to conjugate biomelecules with orthogonal reacting groups at specific sites. The synthesis of UDP-2-(2-ketopropyl)galactose has been previously carried out, albeit with difficulty and low efficiency. A modified approach has been developed for the synthesis of UDP-2-(2-ketopropyl)glucose and UDP-2-(2-ketopropyl)galactose, allowing better access to the desired test compounds, the UDP-2-(2-ketopropyl)glucose and UDP-2-(2-ketopropyl)galactose analogs were synthesized in eight steps and 4.8% and 5.3% overall yield, respectively, an improvement over the first generation synthesis involving eight steps and an overall yield of 0.7%. Published by Elsevier Ltd.