Synthesis of novel chiral bidentatephosphite ligands derived from the pyranoside backbone of monosaccharides and their application in the Cu-catalyzed conjugate addition of dialkylzinc to enones
作者:Qing-Lu Zhao、Lai-Lai Wang
DOI:10.1016/j.tetasy.2011.11.003
日期:2011.11
bidentatephosphite ligands, derived from methyl 3,6-anhydro-α-d-glucopyranoside and chlorophosphoric acid diaryl ester, were easily synthesized. These ligands were successfully employed in the Cu-catalyzed asymmetric conjugate 1,4-addition of the organozinc reagents diethylzinc and/or dimethylzinc to enones. The stereochemically matched combination of glucopyranoside and (R)-H8-binaphthyl in ligand 2,4-bis[(R)-1
TBAF Effects 3,6-Anhydro Formation from 6-<i>O</i>-Tosyl Pyranosides
作者:Zachary A. Morrison、Mark Nitz
DOI:10.1021/acs.orglett.0c00045
日期:2020.2.21
3,6-Anhydro sugars are common structures in algal polysaccharides and occur in the furanodictine and sauropunol natural products. We have found that treatment of 6-O-tosylpyranosides with tetrabutylammonium fluoride provides a mild, high-yielding synthesis of 3,6-anhydro sugars. Using O-glycoside substrates, 3,6-anhydropyranosides are isolated and the use of N,O-dimethyl hydroxylamine glycosides yields