保护基

Then Doripenem came into the market in the July ,2005. We studied the synthesis of Doripemen.Firstly, we synthesized the chemical 2 from the starting material------o-hydroxylphenylacylamine through Reformastky reaction, alkylation, Diekmann reaction, enolization, esterification and etc. Secondly, we synthesized the chemical 3 from L — hydroxylproline through the protection of carboxyl, amidogen and hydroxyl group, reduction by NaBr, SN_2 substitution and Mitsumobu reaction.

我们以水杨酰胺为起始原料，经Reformatsky反应、烷基化、Diekmann环合、烯醇化、酯化等反应合成双环母核2；再从L-羟基脯氨酸出发，经酯化保护羧基、保护氨基、保护羟基、硼氢化还原酯得醇、Sn2取代和Mitsumobu反应等合成巯基侧链3；最后由化合物3经脱保护、水解得硫醇，和化合物2在二异丙基乙基胺的作用下缩合，最后Pd／C催化脱保护，历经16步反应最终得到产物多尼培南。

A commercial and practical synthesis rout with-2-(3-acetoxy-l-me-thyl-l~propenyl)-5,5-dimethyl-l,3-dioxane as starting material by couple,oxidation, Ramberg-Backlund and deprotection is chosen and studied in this paper.

本文选择了以2-(3-氯-1-甲基-1-丙烯)-5，5-二甲基-1，3-二噁烷为原料，经偶连、氧化、Ramberg-Bcklund反应及脱保护基四步反应的合成路线，对该中间体进行合成研究。

I closed the document Kaspersky protection tests, the paper Kaspersky Anti-Virus protection is equivalent to the real-time monitoring, if we are open at this time to protect the document, as long as the pandas do not open the folder to burn incense or burning incense Panda do not continue to move, not a comprehensive scan, Kaspersky and Panda burning incense peaceful coexistence can be a long time.

我是关闭了卡巴斯基的文件保护后试验的，卡巴斯基的文件保护就等于卡巴斯基的实时监控，如果我们此时把文件保护打开，只要不打开熊猫烧香所在的文件夹或者熊猫烧香不继续动作，不做全盘扫描，卡巴斯基可以与熊猫烧香和平共处很久。

The two chiral centers of these compounds were also built by using Evans asymmetric aldolization.

在最后一部分的工作中，研究了IBX在选择性脱硫醇和TES硅醚保护基中的应用。

Aldol condensation 2, 5-dimethoxymethoxyacetophone with 2, 4, 6 -tri methoxymethoxybenzendehyde, then hydrogenation, reductive, the key intermediate 83 (84) of natural product 3, 5, 7, 2′, 5′- pentahydroxyflavan, was obtained; Mini reviewed EGCg activity, Then gallic acid and phloroglucin were used to synthsis EGCg, The key intermediate Chalcone 109 of EGCg was abtained through 7 steps from gallic acid.

重点介绍了以没食子酸为原料，经酯化，保护，还原，氧化，格氏反应，氧化六步反应得到3，4，5-三苄氧基苯乙酮，以间苯三酚为原料，经维斯迈尔反应，苄基保护，甲氧甲氧基保护三步反应得到2，4-二苄氧基-6甲氧甲氧基苯甲醛，酮106与醛108经羟醛缩合得到EGCg重要反应中间体查尔酮109。

Study on the Approach and the Medchine for the Deprotection of Silyl Ether by Sodium Periodate

过碘酸钠去硅醚保护基方法及机理的研究在线阅读整本下载分章下载分页下载

The segments 〓 and 〓 were coupled via Cadiot-Chodkiewcz reaction to afford the intermediate 〓. After the silyl protective groups were removed by TBAF from 〓, we accomplished the stereoselective total synthesis of the target molecule-(11S, 16S)- Oplopandiol Acetate〓.

通过中间体化合物〓和〓的Cadiot-Chodkiewiza炔炔偶联反应得到了中间体化合物〓，再用TBAF脱除保护基完成了目标化合物〓的首次全合成，确证其绝对构型为11S、16S。

The green synthesis of nitrate esters using dinitrogen pentoxide (N2O5) as nitrating agent was briefly summarized.

评述了N2O5为硝化剂制备硝酸酯类含能材料的绿色合成技术，分析了N2O5-有机溶剂硝化、N2O5-固体载体硝化和引入保护基硝化等三种体系工艺的过程和特点，展望了各硝化体系的发展前景。

The hydroxyl groups can be changed into esters,ethers,acetals and ketals,etc.

最常用的羟基保护基主要有三大类：酯类、醚类和缩醛或缩酮类。

NaBH4 reduction of the iodides in DMSOfollowed by deprotection of Boc gave theα-methylamine in 61.5% yield.

得到的碘化物再用NaBH4还原，并且脱除Boc保护基可制备出α-甲基胺。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。