摘要
合成表征了红霉素A 9 ( 1 异丙氧基环己基 )肟的E和Z异构体 ,并在丙酮 -水混合溶剂中培养出了前者的单晶 .X射线衍射表明 ,其结构为正交晶系 ,P2 12 12 1空间群 ,晶胞参数 :a =2 .3 10 1( 5 )nm ,b =2 .3 761( 5 )nm ,c =0 .970 66( 19)nm ,V =5 .3 2 79( 18)nm3 ,Z =4,μ =0 .0 88mm-1,F( 0 0 0 ) =2 0 64 ,Dc=1.176g/cm3 .E 红霉素A 9 ( 1 异丙氧基环己基 )肟的晶体结构图明显表明 1 异丙氧基环己基保护基确实使十四元大环的构象发生了扭曲 ,使 6 OH的周围空间不再拥挤 ,从而导致 6 OH甲基化的选择性提高 .
E- and Z-isomers of erythromycin A 9-(1-iso-propoxycyclohexyl)oxime have been synthesized and characterized. The crystal structure of E-isomer was determined by X-ray single-crystal structure analysis. The crystal belongs to orthorhombic system, P2(1)2(1)2(1) space group with a = 2.3101(5) nm, b 2.3761(5) m, c = 0.97066 (19) nm, V = 5.3279(18) nm(3), Z = 4, mu = 0.088 mm(-1), F(000) = 2064, D-c = 1.176 g/cm(3), R-1 = 0.0505, wR(2) = 0.0775 for 6747 unique reflections. The torsion angles of its fourteen-member erythrolide clearly elucidated the origin of regioselectivity occurring at 6-hydroxyl in the O-methylation of erythromycin A.
出处
《有机化学》
SCIE
CAS
CSCD
北大核心
2003年第8期841-845,共5页
Chinese Journal of Organic Chemistry
基金
国家经贸委技术创新 (No.0 1BK 0 0 9)资助项目
