作者:Hui Liu、Si-Yu Zhou、Jin-Xi Liao、Jian-Song Sun、Yuan-Hong Tu
DOI:10.1055/a-1346-5650
日期:2021.5
Taking advantage of the reliable stereocontrol capability of DMNPA group via long-distance-participation (LDP) effect as well as the mild and efficient deprotection conditions, the first and highly efficientsynthesis of digoxin was achieved through a nine-step longest linear sequence with 41% overall yield.
Synthetic Investigation toward the D-Ring-Functionalized Cytotoxic Oleanane-Type Saponins Pithedulosides D and E
作者:Shi-Jie Ge、Yuan-Hong Tu、Jian-Hui Xia、Jian-Song Sun
DOI:10.1002/ejoc.201700707
日期:2017.7.25
application of both Schmidt and Yu glycosylations, the first total syntheses of the echinocystic acid saponins pithedulosides D and E, the two antitumoral and representative D-ring-functionalized oleanane-type saponins, were achieved. Benefitting from the applied convergent synthetic strategy, the echinocystic acids could be synthesized in overall yields of as high as 71 and 76 % through four linear steps
adaptable to the synthesis of congeners and analogues, as exemplified by the ready synthesis of ds‐echinoside A and echinoside B, and thus will facilitate in‐depth studies on the promising biological effects of echinoside A. Moreover, the present synthesis demonstrates the feasibility of synthetic access to the characteristic complex triterpene glycosides that occur ubiquitously in seacucumbers.
Dual-Participation Protecting Group Solves the Anomeric Stereocontrol Problems in Glycosylation Reactions
作者:Hui Liu、Thomas Hansen、Si-Yu Zhou、Guo-En Wen、Xu-Xue Liu、Qing-Ju Zhang、Jeroen D. C. Codée、Richard R. Schmidt、Jian-Song Sun
DOI:10.1021/acs.orglett.9b03321
日期:2019.11.1
The 2,2-dimethyl-2-(ortho-nitrophenyl)acetyl (DMNPA) group permits, via robust neighboringgroupparticipation (NGP) or long distance participation (LDP) effects, the stereocontrolled 1,2-trans, 1,2-cis, as well as β-2,6-dideoxy glycosidic bond generation, while suppressing the undesired orthoester byproduct formation. The robust stereocontrol capability of the DMNPA is due to the dual-participation