内酯化

The reaction of polyfluoroalkyl iodides with 4-pentenoic acids initiated by sodium dithionite was realized to give polyfluoroalkyl substituted lactones.

我们研究了多氟烷基碘代烷与4-戊烯酸类化合物等在连二亚硫酸钠引发下的反应，得到了氟烷基取代的内酯化合物，我们将该反应称为氟烷基化内酯化反应；并建立了一个利用该反应合成含氟内酯的新方法，首次利用氟烷基化内酯化反应进行高立体选择性双环含氟内酯及手性含氟内酯等的合成，已合成含氟内酯新化合物50余种。

Vanillin 58 was used as starting material, which underwent methylation, bromination, acetalization, lithiation followed by nucleophlic addition to aldehyde, Diels-Alder reaction, selective reduction and lactonization to produce diphyllin in an overall yield of 38%(7 steps).

这个方法从香兰素58开始，经过甲基化、溴化、成乙二醇缩醛反应、锂化而后对醛亲核加成、Diels-Alder反应、选择性还原反应和内酯化反应共7步，最后得到diphyllin，总产率38％。

N-Carbobenzoxy-L-homoserinelactone was prepared via N-alkylation reaction of L-methionine and iodoacetamide with benzyl chloroformate as amino protecting agent.

以L-蛋氨酸为原料，氯甲酸苄酯为氨基保护试剂，与碘乙酰胺(I2微量)内酯化反应，合成N-苄氧羰基-L-高丝氨酸内酯。

In a similar way, using N,N\'-dibenzyl tartamide as auxiliary,-(2-methyl)allyl-2-chloro-phenyl-methyl azide, a vital intermediate of Repaglinide, can be prepared via asymmetric allylation of o-chlorobenzaldehyde in

产物经氧化和碘加成内酯化反应得到阿伐他汀中间体(3R，5S)-3-羟基-5-碘甲基戊内酯(10)；将N-苄基酒石酸二酰胺用于邻氯苯甲醛的不对称烯丙基化反应以较高光学收率得-甲基烯丙基-2-氯苯基-甲基醇

Ruthenium-modified solid catalyst Ru-Co2-CeO2 was applied to the lactonization of diols in the presence of molecular oxygen and achieved highly efficient catalytic performance.

将钌改性的固体催化剂Ru-Co2-CeO2用于以分子氧作为氧化剂的二元醇的催化氧化内酯化反应中，发现该催化剂具有很好的催化反应性能。

The diastereo-selective lactones 57～58 was obtained by the polyfluoroalkyl -lactonization of S--2-methyl-4-pentenoic acid under the reaction conditions mentioned above.

以S--2-甲基-4-戊烯酸进行上述内酯化反应，可得到具有立体选择性的产物57a，57b，58a，58b。

Such structural complexity is further enhanced by O-acetylation, esterification, lactonization, as well as other forms of substitutions, reflecting significance of carbohydrates in cell recognition.

细胞表面上糖缀合物的糖链经常以多/寡聚体形式存在，并且结构复杂，常常大量表达唾液酸、糖醛酸、硫酸化糖基等酸性糖，并发生O-乙酰化、酯化和内酯化等修饰。

Based on our intensive studies on the lactonization of oligo/polysialic acids, we proposed for the first time that the lactone-ring formation of oligo/polysialic acids has three stages. We also provided a novel model to explain the conformational changes of oligo/polysialic acids caused by the repulsing forces among the carboxyl groups of sialic acid residues. Our results should provide novel approaches for further investigation of the structural-functional relationships of oligo/polysialic acids.

在对多/寡聚唾液酸内酯化过程进行深入研究的基础上，于国际上率先提出多/寡聚唾液酸内酯的形成具有三个阶段的观点，并首创性地提出了羧基排斥所致多/寡聚唾液酸分子空间构象改变的模型，为深入研究多/寡聚唾液酸结构与功能的关系提供了新生长点。

Chiral centers of C5 and C8 are directly constructed in the key step of the diastereoselective propargylation from D--tartrate. The methylation and subsequent methoxycarbonylation result in desymmetrization of the terminal dialkynes. The α,β-unsaturated δ-lactone is synthesized after partial hydrogenation and lactonization.

由非天然酒石酸出发，利用双向非对映选择性的炔丙基化反应，在一步反应中同时构建C5和C8手性中心；然后通过末端炔基的甲基化、甲酯基化，延长碳链并对分子去对称化；内酯化得到关键中间体α，β-不饱和六元内酯，再经多步反应转化得到8-epi--Boronolide。

Through diazotization-lactonization,esterification, reduction, ether formation and double bond formation,the optically active--γ-benzyloxy methy-γ-butanolideXXIII and--γ-benzyloxy mothy-γ- butenolideXXV were preparedstarting from L-glutamic acid.

本论文采用易得的L-谷氨酸为原料，经重氮化-内酯化、酯化、还原、醚化和形成双键五步反应，合成了光学活性的化合物XXIII和XXV(Scheme 6，P.63)。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。