AIM:To simplify the procedure for synthesis of 2′ acetyl 12 hydroxy 2,3,10,11 dianhydro 6 O methyl erythromycin A(7). METHOD:Selective removal of the cladinose residue of clarithromycin was accomplished by the treatm...AIM:To simplify the procedure for synthesis of 2′ acetyl 12 hydroxy 2,3,10,11 dianhydro 6 O methyl erythromycin A(7). METHOD:Selective removal of the cladinose residue of clarithromycin was accomplished by the treatment with aqueous HCl at room temperature. Acetylation with acetic anhydride/triethylamine in methylene chloride provided the 2′ protected macrolide(9) with high yield. Then 2′ acetyl 12 hydroxy 2,3,10,11 dianhydro 6 O methyl erythromycin A(7) was synthesized from 9 which was treated with excess p toluenesulfonic acid and triethyl orthoformate at 50 ℃ in acetone.RESULT:The overall yield was 27%. The structure of the product was confirmed by IR,MS,NMR and elemental analysis. CONCLUSION: Our synthetic procedure of 7 was shorter and more convenient than that reported by Abbott Laboratories.展开更多
在催化剂过氧磷钨酸十二烷基吡啶盐(Cat-PW4)的作用下,α-蒎烯与H2O2反应生成主要产物(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇。不同反应条件对反应转化率和选择性的实验结果表明,最佳反应条件为:12.8 mmolα-蒎烯、5 m ...在催化剂过氧磷钨酸十二烷基吡啶盐(Cat-PW4)的作用下,α-蒎烯与H2O2反应生成主要产物(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇。不同反应条件对反应转化率和选择性的实验结果表明,最佳反应条件为:12.8 mmolα-蒎烯、5 m L溶剂三氯甲烷、0.2 g催化剂、3.3 m L 30%H2O2,反应温度40℃,反应时间3 h,α-蒎烯转化率和产物的选择性分别为94.7%和39.8%。反应结束后,该产物存在于水相和有机相中,通过萃取和重结晶分离提纯,得率11%,纯度达到98%;其分子结构通过红外光谱、紫外光谱、1H核磁共振谱、13C核磁共振谱、低分辨率质谱及高分辨率质谱确证。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AIM:To simplify the procedure for synthesis of 2′ acetyl 12 hydroxy 2,3,10,11 dianhydro 6 O methyl erythromycin A(7). METHOD:Selective removal of the cladinose residue of clarithromycin was accomplished by the treatment with aqueous HCl at room temperature. Acetylation with acetic anhydride/triethylamine in methylene chloride provided the 2′ protected macrolide(9) with high yield. Then 2′ acetyl 12 hydroxy 2,3,10,11 dianhydro 6 O methyl erythromycin A(7) was synthesized from 9 which was treated with excess p toluenesulfonic acid and triethyl orthoformate at 50 ℃ in acetone.RESULT:The overall yield was 27%. The structure of the product was confirmed by IR,MS,NMR and elemental analysis. CONCLUSION: Our synthetic procedure of 7 was shorter and more convenient than that reported by Abbott Laboratories.
文摘在催化剂过氧磷钨酸十二烷基吡啶盐(Cat-PW4)的作用下,α-蒎烯与H2O2反应生成主要产物(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇。不同反应条件对反应转化率和选择性的实验结果表明,最佳反应条件为:12.8 mmolα-蒎烯、5 m L溶剂三氯甲烷、0.2 g催化剂、3.3 m L 30%H2O2,反应温度40℃,反应时间3 h,α-蒎烯转化率和产物的选择性分别为94.7%和39.8%。反应结束后,该产物存在于水相和有机相中,通过萃取和重结晶分离提纯,得率11%,纯度达到98%;其分子结构通过红外光谱、紫外光谱、1H核磁共振谱、13C核磁共振谱、低分辨率质谱及高分辨率质谱确证。
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.
