合成地

After that, we introduced a new approach to synthesis of valiolamine, by a series of reaction to the carbon-carbon double bond from the substrate of valienamine, including epoxidation, hydrogenolysis and so on, and obtained the aim product finally.

在完成上述合成路线后，本文通过提出了一条全新的合成伏格列波糖重要中间体valiolamine的路线，即采用对底物valienamine中的碳-碳双键进行环氧化、氢解等一系列反应，成功地制备出所需的中间体，研究全新的合成伏格列波糖的路线，研究结果证实：该新路线已经被打通。

This thesis consists of four parts as follows: Part I: ReviewThe purpose of the present review is to summarize the organic chemistry of polyvalent iodine compounds regarded as Chlorides, Fluorides, Oxidize reagents in the field of organic synthesis, especially focus on their synthetic application and space structure, there are lots of reaction examples to illustrate the incomparable merits of organic polyvalent iodine compounds in the synthesis of some drugs and natural products.

本论文由以下四部分组成：第一部分：文献综述本部分比较全面地回顾了有机含碘化合物作为氯化、氟化、氧化试剂在精细有机合成中的应用，主要针对含碘试剂的合成及其结构做了比较详细的综述，并且列举了大量反应实例引证了这种类型试剂在药物及天然产物合成方面具备的优势。

Semiconservative replication :The two strands of DNA double helix are separated, each strand serves as a template for the synthesis of a new complementary strand, producing two daughter molecules. Each daughter molecule has one parental strand and one newly synthesized strand.

半保留复制： DNA 生物合成时，母链 DNA 解开为两股单链，每股单链分别作为模板，以 dNTP(dATP 、 dGTP 、 dCTP 、 dTTP)为原料，按照碱基配对(A － T 、 G － C)规律与模板上的碱基配对，经依赖 DNA 的 DNA 聚合酶催化，合成一条与模板互补的新链，新形成的两个子代 DNA 与亲代 DNA 碱基序列一致，子代 DNA 分子中一股单链是从亲代完整地接受过来，另一股单链是新合成的，故称为半保留复制。

We developed a new work-up procedure for thesynthesis of 5,15-diphenylporphyrin. This modification has been proved to bevery efficient.

在合成工作中，我们改进了5，15-二苯基卟啉合成的后处理过程，极大地提高了合成功效。

Reaction of 5'-O-p-methoxytrityl-thymidine with 1, 1'-carbonyl-diimidazole gave the 3'-O-carbonylimidazolide, which was condensed in high yield with 3'-O-protected thymidine to give a dithymidine carbonate. In the same way, we obtained the protected trithymidine dicarbonate. After deprotection, we obtained quantatively the trithymidine dicarbonate.By the same stratagy, we completed the synthesis of dithymidine sulfite.It was shown that allyl can be used as a good protection group for hydroxyl of ribose in the synthesis of oligonucleotides consisting in some unstable nucleotide analogues.

我们在第一部分工作的基础上，以烯丙基作为3'-OH的保护基合成了保护的三胸苷碳酸酯以及二胸苷亚硫酸酯，用我们所得的脱保护条件进行了脱保护研究，得到了三胸苷碳酸酯以及二胸苷亚硫酸酯，并研究了它们合成中的一些化学问题，结果表明：烯丙基能很好地运用于这两类寡核苷酸类似物的合成中，其脱保护条件为中性，不会影响碳酸酯键及亚硫酸酯键。

A few spiro ligands have been successfully synthesized and applied in asymmetric catalysis .

手性螺环配体的合成及其在不对称催化反应中的应用是不对称合成和催化研究中重要的研究领域之一，一些手性螺环配体被合成出来并成功地应用于不对称催化反应中。

To further testify the high efficiency of these new reagents in the synthesis of sterically hindered peptides, we successfully synthesized the extensively -N-methylated peptide moiety of the antineoplastic and lipophilic depsipeptide Dolastatin 15 using reagent BEP and FEP. We also synthesized the highly hindered tetrapeptide segment of Cyclosporin A using reagent BEMT and BEP, respectively.

为进一步检验这类吡啶正离子型缩合剂在有空间位阻的多肽合成中的性能，我们以BEP和FEP为缩合剂，成功地合成了具有抗肿瘤活性的亲脂性酯肽Dolastatin 15分子中高N-烷基化的肽链部分；分别以BEMT和BEP为缩合剂合成了生物活性肽Cyclosporin A中空间位阻最大的四肽片断。

Benzoylated phenyl a - and B - 2 - thio - D - fructofuranosides were synthesized and coupled with protected sucrose acceptor to synthesize a - D - fructofuranoside - linkage stereospecifically by employing NIS/AgOTf as catalysts.

在果糖的合成研究中，合成了四苯甲酰基苯基果糖硫苷，并首次将其用作糖苷化反应的给体，在NIS/AgOTf的促进之下，与乙酰化保护的蔗糖受体反应，从而以高产率立体专一地合成了α构型的呋喃果糖苷。

A new convenient synthesis of a series of 1-aryl-2-propanones using aromatic amines as precursors, via diazo reaction and improved Meerwein arylation reaction under mild conditions, was achieved. In addition, 1-[3,5-bisphenyl]-2-propanone is a new compound among the synthesized compounds. This approach is an efficient synthetic method for the aryl-propanones with the different substituting groups.

以芳香胺为原料，经重氮化和改进的Meerwein芳基取代反应，合成了一系列的1-芳基－2-丙酮，其中1-（3，5-二三氟甲基苯基）2-丙酮是一个新化合物改进后的方法简化了合成步骤，提高了收率，可方便地用于在苯环上具有不同取代基的芳基丙酮的合成。

And the strengthening mechanism can be described as follows: WC cemented carbides have interlaced short-clubbed grain, and in the bend strength test, the microcrack generates at WC/WC grain boundary, and may be blocked by interlaced fine-clubbed grains during extending, which induce the intergranular pulling-out. Due to the pulling-out mechanism, fracture-extend energy is greatly expended, thus bend strength is increased. The wear mechanism is groove wear and spalling of WC grains.

热机械合金化合成的WC-Co硬质合金比传统方法制备的同类WC合金具有更高的强度，其机理是：热机械合金化合成的WC合金具有交替排列的短棒状组织，在三点弯曲试验中，微裂纹萌生于WC/WC晶界位置，受到交错排列的短棒状晶粒的阻碍，裂纹扩展以短棒状晶粒的拔出方式进行，极大地消耗了裂纹扩展的能量，从而提高了弯曲强度；合成试样的摩擦磨损过程以犁沟磨损和WC颗粒的剥落为主要特征。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！