立体化学的

By ~(31)P NMR, it was found that the racemization of amino acids was minimized. And it seams that L-amino acid has different reaction acticity from the D-amino acids.

其次，从磷化学的角度研究了氨基酸的立体化学对酯交换反应的结构效应，发现了以磷酰基保护的氨基酸以及含磷缩合试剂的方法进行多肽的合成，氨基酸消旋现象很少发生。

John Cornforth (b. 1917) and Vladimir Prelog (1906-98) shared a 1975 Nobel Prize for work on stereochemistry and stereoisomerism of alkaloid s, enzymes, antibiotics, and other natural compounds.

康福思和普雷洛格在立体化学以及生物碱、、抗生素和其它天然化合物的立体异构方面做了许多工作，因而共获1975年的诺贝尔奖。

John Cornforth (b. 1917) and Vladimir Prelog (1906-98) shared a 1975 Nobel Prize for work on stereochemistry and stereoisomerism of alkaloids, enzymes, antibiotic s, and other natural compounds.

康福思和普雷洛格在立体化学以及生物碱、、抗生素和其它天然化合物的立体异构方面做了许多工作，因而共获1975年的诺贝尔奖。

When the 3-keto glycosides was reduced by sodium borohydride, the D-allo configuration was considered the most probable since it has an equatorial arylamino group at C-2 position and reduction of the keto group was considerably less hindered to equatorial attack by borohydride ion to give an axial hydroxyl, than axial attack by borohydride to give an equatorial hydroxyl.

并对反应的立体化学问题进行了讨论，认为该反应的立体专一性是由于向下直立键上的1-位α-甲氧基和2-位向下平伏键上芳胺基大基团的共同影响，造成内侧进攻受阻，而使得氢负离子只能从外侧进攻的结果。

On the basis of our research on Stellera chamaejasme L. and the literatures, the spectral and structural characteristics, the stereochemical researching methods, the distribution in the 3 subtribes of Thymeleaceae and chemotaxonomy of biflavonoids were concluded. We found that biflavonoids played a very important role in the chemotaxonomy of Thymelaeaceous plants.

通过对瑞香狼毒中双黄酮类化合物的研究，结合文献，总结了瑞香科中双黄酮类化合物的结构特点、波谱规律和立体化学研究方法；同时对双黄酮类化合物在瑞香科植物中的分布规律进行了总结，发现双黄酮类化合物在瑞香科的植物化学分类学方面具有重要作用。

This Ph.D. thesis describes further studies on theformation of fluorinated phosphorus ylide-anions resultingfrom organometallics and their reactions, stereochemistry andapplications in organic synthesis. We found that inverse stereochemical results wereobserved in the reaction of the fluorinated ylide-anions withvarious proton donors.

本博士论文进一步研究了用有机金属试剂对含氟膦叶立德的亲核加成导致的叶立德阴离子的反应性、立体选择性及其在有机合成中的应用：首次发现含氟叶立德阴离子在与不同的质子化试剂作用时，反应呈现完全相反的立体化学结果。

It is found that the stereochemistry of the reactions of telluronium allylide,crotonylide and trimethylsilyallylide with α,β-unsaturated esters and amides can be tuned by thechoice of reaction conditions.

利用反应条件的变化首次实现了烯丙基、巴豆基、含硅烯丙基碲叶立德与α，β-不饱和酯、酰胺进行环丙烷反应的立体化学调控，能高立体选择性地、高效率地合成两种不同几何异构体中的一个。

This requirement may be satisfied by the submission of information such as the following: name (generic name, chemical name, code number); Chemical Abstracts Service number if available; description (e.g., appearance, color, physical state); molecular formula and molecular weight; structural formula (including ionic state if applicable); stereochemistry identifying chiral centers, cis-trans isomerism, etc.

该要求可以通过提供下述信息来满足：名称（通用名、化学名、编码等）、化学摘要服务编码、性状描述（如：外观、颜色、物理状态）、分子式和分子重量、结构式、立体化学（找出手性中心、顺式反式异性等）、对映结构体比率（如：外消旋物、规定的异构体、对映异构物和固态形式的混合物）、溶解度概况、分配系数、溶液 pH 值、解离常数、熔点或沸点、折射率、比重。

Enantiomer or solid-state form ratios (e.g., for racemates, and for defined admixtures of isomers or enantiomers or solid-state forms); solubility profile (aqueous and nonaqueous as applicable); partition coefficients; solution pH; dissociation constant; melting or boiling point; refractive index; specific gravity.

该要求可以通过提供下述信息来满足：名称（通用名、化学名、编码等）、化学摘要服务编码、性状描述（如：外观、颜色、物理状态）、分子式和分子重量、结构式、立体化学（找出手性中心、顺式反式异性等）、对映结构体比率（如：外消旋物、规定的异构体、对映异构物和固态形式的混合物）、溶解度概况、分配系数、溶液pH值、解离常数、熔点或沸点、折射率、比重。

Enantiomer or solid-state form ratios (e.g., for racemates, and for defined admixtures of isomers or enantiomers or solid-state forms); solubility profile (aqueous and nonaqueous as applicable); partition coefficients; solution pH; dissociation constant; melting or boiling point; refractie index; specific graity.

该要求可以通过提供下述信息来满足：名称（通用名、化学名、编码等）、化学摘要服务编码、性状描述（如：外观、颜色、物理状态）、分子式和分子重量、结构式、立体化学（找出手性中心、顺式反式异性等）、对映结构体比率（如：外消旋物、规定的异构体、对映异构物和固态形式的混合物）、溶解度概况、分配系数、溶液pH值、解离常数、熔点或沸点、折射率、比重。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失