3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Th...3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Thr with unprotected hydroxyl group on their side chain.Thus,DEPBT is useful for the synthesis of peptide alcohols,which have attracted much attention not only as the ligands but also as the enzyme inhibitors.A side reaction of DEPBT was found in the synthesis of Boc-β-Ala-HisOMe with unprotected imidazolyl group.In this paper,the discovery of this side reaction and the confirmation of the structure of this side product were reported.In addition,the influence of different reaction conditions on the side reaction were studied.Imidazolyl group was a key factor to cause the side reaction,excess DEPBT and high reaction temperature promoted the side reaction.展开更多
2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were inve...2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were investigated.The results showed that the optimum conditions were as follows:6methyl5heptene2one:1,2Propandiol:catalyst:dehydrating agent is 1 mol:15mol∶12g∶200ml;reaction temperature was reflux temperature;reaction time was 25h.The yield was above 915% under the optimum conditions.The catalyst can be used repeatedly.展开更多
The title compound N,N′ ditosyl 3 methoxyimino 1,5 diaza cyclooctane(4) has been prepared by two methods,the reactions of all steps are carried out under very moderate conditions and the overall yield is high.The str...The title compound N,N′ ditosyl 3 methoxyimino 1,5 diaza cyclooctane(4) has been prepared by two methods,the reactions of all steps are carried out under very moderate conditions and the overall yield is high.The structures of the new compounds 2,3,4 are characterized by elemental analysis,IR, 1H NMR and MS spectroscopy.展开更多
A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)...A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.展开更多
文摘3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Thr with unprotected hydroxyl group on their side chain.Thus,DEPBT is useful for the synthesis of peptide alcohols,which have attracted much attention not only as the ligands but also as the enzyme inhibitors.A side reaction of DEPBT was found in the synthesis of Boc-β-Ala-HisOMe with unprotected imidazolyl group.In this paper,the discovery of this side reaction and the confirmation of the structure of this side product were reported.In addition,the influence of different reaction conditions on the side reaction were studied.Imidazolyl group was a key factor to cause the side reaction,excess DEPBT and high reaction temperature promoted the side reaction.
文摘2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were investigated.The results showed that the optimum conditions were as follows:6methyl5heptene2one:1,2Propandiol:catalyst:dehydrating agent is 1 mol:15mol∶12g∶200ml;reaction temperature was reflux temperature;reaction time was 25h.The yield was above 915% under the optimum conditions.The catalyst can be used repeatedly.
文摘The title compound N,N′ ditosyl 3 methoxyimino 1,5 diaza cyclooctane(4) has been prepared by two methods,the reactions of all steps are carried out under very moderate conditions and the overall yield is high.The structures of the new compounds 2,3,4 are characterized by elemental analysis,IR, 1H NMR and MS spectroscopy.
文摘A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.
