杂环原子

During these years (1997-2000) in the research area of annonaceous acetogenins 5 natural products and a number of chiral-pure analogs of annonaceous acetogenins have been synthesized using sugars as the starting materials. Their high activity and selectivity against cell line of colon tumor and a relationship between activity and configuration have been found too. In the respect of inhibitor of sialidase two new methodologies for the synthesis of chiral-pure 3-deoxy-ulosonic acid using hetero-Diels-Alder reaction or asymmetric propargylation as the key reaction were developed. On the topic of anti-leukemia marine natural product clavulactone a synthetic method based on the free radical cyclization and starting from sugar has been developed. In other title of PKC inhibited agent sphingosine a new synthetic route with SN2' as the key reaction has also been disclosed.

项目期间（1997-2000）在番荔枝内酯方面从糖出发合成了五个天然产物和一批手性纯的类似物，它们对肠癌细胞有很高的活性和选择性，并与构型有关；在唾液酸酶抑制剂方面发展了二类全新手性纯高碳糖的合成方法－杂原子D－A反应或丙炔基不对称加成为关键的反应；抗白血病海洋天然产物群柱虫内酯方面研究了由糖出发和自由基环化反应的合成方法；对PKC 起抑制作用的鞘氨醇方面也开创了新的合成途径－由糖出发并以SN2'反应为关键反应。

Totally 17 new type of fulvene ligands have been synthesized by the reaction of substituted-benzoyl chloride with Cp and substituted Cp anions. All the new compounds are fully characterized by infrared spectroscopy,!

我们利用含芳香取代基的环戊二烯丛负离子与含-CN、-I、-CO_2CH_3等配位有机基团的芳酰氯反应成功地合成了17个既含芳香基团又含杂原子配位基团的刚性共轭富烯类配体。

The facts indicate that apart from the asymmetric induction of chiral diamine backbone,sterically hindered substitute groups on the aromatic rings,and the presence of sp~3-hydridized amino donors and its N,N\'-disubstituted groups in chiral SalanCrX complexes all play important roles in controlling polymer stereochemistry and enantioselectivity.

研究发现除了手性二胺骨架的不对称诱导作用，苯环上的大位阻取代基、N，N\'-二取代基的位阻作用以及N原子上sp~3杂化的供电子效应都对调控聚合物的区域和对映体选择性有很大作用。

The complex is applied to the ring cleavage reaction of various organic boron agents to the hetero atom norbornadiene.

该类络合物适用于各类有机硼试剂对杂原子降冰片二烯的不对称催化的开环的反应。

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。