排序方式: 共有34条查询结果,搜索用时 0 毫秒
31.
Valeria Di Bussolo Salvatore Princiotto Vittorio Bordoni Elisa Martinelli Lucilla Favero Stefano Crotti Gloria Uccello Barretta Federica Balzano Mauro Pineschi Paolo Crotti 《Tetrahedron》2019,75(33):4425-4443
Upon treatment with the metal enolates of methylene active compounds (dimethyl malonate and dibenzoylmethane) (C-nucleophiles) and benzyl carbamate (N-nucleophile), d-allal- and d-galactal-derived vinyl epoxides are stereoselectively transformed, in a single step, into diastereoisomeric, highly functionalized, enantiopure cis- and trans-2,5-disubstituted-2,5-dihydrofurans. 相似文献
32.
Valeria Di Bussolo 《Tetrahedron letters》2010,51(38):4937-4941
The glycosylation of alcohols by the new 2-O-MEM-substituted d-galactal-derived allyl epoxide affords the corresponding alkyl 2-O-MEM-3-deoxy-β-d-threo-hex-2-enopyranosides through a completely 1,4-regio- and a highly to completely substrate-dependent stereoselective glycosylation processes. The glycosides obtained can be regioselectively transformed into corresponding 3-deoxy-β-O-glycosides, 3-deoxy-β-d-threo-hexopyranosid-2-uloses, and 3,4-dideoxy-β-d-glycero-hex-3-enopyranosid-2-uloses, which are useful synthetic tools for further transformations. 相似文献
33.
J.S Yadav B.V.Subba Reddy M Srinivas A Prabhakar B Jagadeesh 《Tetrahedron letters》2004,45(31):6033-6036
2,3-Dihydro-4H-pyran-4-ones derived from d-glucal undergo rapid condensation with aryl hydrazines in the presence of montmorillonite KSF clay under mild conditions to afford a novel class of chiral 5-substituted pyrazoles in good yields with high selectivity. The stereochemical assignments of the products were achieved by NMR studies. 相似文献
34.
Hexafluoroisopropanol (HFIP) is explored as an effective medium for the synthesis of 2,3-unsaturated glycosides through allylic rearrangement of 3,4,6-tri-O-acetyl glucal. This metal-free, exclusively solvent-promoted Ferrier glycosylation, affords products in good to excellent yields and with good α-selectivity. 相似文献