Aim To develop a concise method for the synthesis of bicyclic azasugar and thiosugar with novel scaffold. Methods The two primary hydroxyl groups of compound 1 were selectively protected with tosyl cloloride in pyridi...Aim To develop a concise method for the synthesis of bicyclic azasugar and thiosugar with novel scaffold. Methods The two primary hydroxyl groups of compound 1 were selectively protected with tosyl cloloride in pyridine, followed by ring-closure with sodium sulfide or primary amine to form the oxy-bridged bicyclic molecules in good yields. Results Two bicyclic azasugars and a thiosugar were produced from L-sorbose in several steps. Conclusion The described procedures provide an efficient method to synthesize bicyclic azasugar and thiosugar with novel scaffold as potential glycosidase inhibitors.展开更多
An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-ll-oxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2,7]trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Bi...An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-ll-oxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2,7]trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Biginelli condensation and intramolecular Michael-addition by using magnesium bromide as an inexpensive and easily available catalyst in a solvent-free condition is described. The structural elucidation of the product is reported by ^1H- and ^13C NMR spectra. The product can also be identified by its EI TOF mass spectrometry based on the molecular ion at m/s 246（10%） and on the fragment ions in which two nitrogen atoms are remained. Three kinds of characteristic fragmentation pathways from the molecular ion were observed. One is the loss of the OH radical to form the dihydropyrimidinone cation at m/z 229（48%）, followed by elimination of a molecular methane forming the pyrimidinone cation at m/z 213（27%）. The second is the cleavage of the C6H4OH radical, and the formation of the dihydropyrimidinone cation at m/z 153（24%）. The third one is the loss of MeC-O radical to afford the oxygen-bridged fragment ion at m/z 203（33%）.展开更多
基金We thank the National Science Foundation of China(NSFC,N0.20372003)for financial support.
文摘Aim To develop a concise method for the synthesis of bicyclic azasugar and thiosugar with novel scaffold. Methods The two primary hydroxyl groups of compound 1 were selectively protected with tosyl cloloride in pyridine, followed by ring-closure with sodium sulfide or primary amine to form the oxy-bridged bicyclic molecules in good yields. Results Two bicyclic azasugars and a thiosugar were produced from L-sorbose in several steps. Conclusion The described procedures provide an efficient method to synthesize bicyclic azasugar and thiosugar with novel scaffold as potential glycosidase inhibitors.
基金This work was supported by the Natural Science Foundation of China （No.20425309）.
文摘An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-ll-oxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2,7]trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Biginelli condensation and intramolecular Michael-addition by using magnesium bromide as an inexpensive and easily available catalyst in a solvent-free condition is described. The structural elucidation of the product is reported by ^1H- and ^13C NMR spectra. The product can also be identified by its EI TOF mass spectrometry based on the molecular ion at m/s 246（10%） and on the fragment ions in which two nitrogen atoms are remained. Three kinds of characteristic fragmentation pathways from the molecular ion were observed. One is the loss of the OH radical to form the dihydropyrimidinone cation at m/z 229（48%）, followed by elimination of a molecular methane forming the pyrimidinone cation at m/z 213（27%）. The second is the cleavage of the C6H4OH radical, and the formation of the dihydropyrimidinone cation at m/z 153（24%）. The third one is the loss of MeC-O radical to afford the oxygen-bridged fragment ion at m/z 203（33%）.
