5，6-O-苯亚甲基-L-抗坏血酸和5，6-O-苯亚甲基-D-异抗坏血酸的合成  

Study on the synthesis of 5,6-O-benzylidene-L-ascorbic acid and 5,6-O-benzylidene-D-isoascorbic acid

作　　者：郑大贵[1] 余衍文[1] 肖竹平[1] 余明辉[2] 

机构地区：[1]上饶师范学院江西省普通高校应用有机化学重点实验室,江西上饶334001 [2]中国科学院化学研究所,北京100080

出　　处：《化学试剂》2009年第1期1-4,共4页Chemical Reagents

基　　金：江西省普通高校重点实验室科技计划项目(赣教技字2006-302号,赣教技字2007-401号)

摘　　要：采用N,N-二甲基乙酰胺(DMAc)为溶剂、对甲苯磺酸(TsOH)为催化剂、环己烷为带水剂,苯甲醛与L-抗坏血酸反应生成(顺)-5,6-O-苯亚甲基-L-抗坏血酸和(反)-5,6-O-苯亚甲基-L-抗坏血酸,与D-异抗坏血酸反应生成(顺)-5,6-O-苯亚甲基-D-异抗坏血酸和(反)-5,6-O-苯亚甲基-D-异抗坏血酸。1HNMR数据表明,两个反应所得到的顺反异构体均为不等量。应用Chemoffice 9.0的3D模块中半经验分子轨道(MOPAC)程序计算的结果表明,两个反应顺式异构体最稳定构象的能量均比反式异构体最稳定构象的能量低,优势产物均可能以顺式异构体为主。以5,6-O-苯亚甲基-D-异抗坏血酸合成为例,用正交实验法优化了合成反应条件。Using p-toluene sulfonic acid as the catalyst, dimethyl acetamide as the solvent and cyclohexane as the water-carrying agent, 5,6- O-benzylidene- L-ascorbic acid and 5,6- O-benzylidene-D-isoascorbic acid were synthesized by the reaction of benzylaldehyde with L-ascorbic acid and the reaction of benzylaldehyde with D-isoascorbic acid, respectively. Whether 5,6- O-benzylidene- L- ascorbic acid or 5, 6- O- benzylidene- D-isoascorbic acid could be obtained as a mixture with different ratios of c/s- and trans-isomers was identified by 1HNMR spectroscopic analysis. The heats of formation （HOF） of c/s- and trans-isomers were calculated by means of the semi-empirical molecular orbital （MOPAC） method attached to the Chemoffice 9.0 software. It was found that the c/s-acetal was more stable than the corresponding trans-acetal and the major product of the reactions was possibly the c/s-acetal. The synthesis conditions were optimized by orthogonal experiments.

关 键 词：5 6-O-苯亚甲基L抗坏血酸 5 6-O-苯亚甲基-D-异抗坏血酸 半经验分子轨道(MOPAC)法 

分 类 号：O621.25[理学—有机化学]