乙硫醇

In order to obtain versatile ulitity of host molecules, three new chiral calix [4] crown ethers containing aza, thio atoms bearing two chiral sites provided by -cysteine ester were synthesized by the condensation of calix [4] arene diacid dichloride with oligoethylene glycol bridged bis-amino acid methyl ester. All new compounds were characterized by NMR, MS and elemental analysis.

以-半胱氨酸为手性源，利用多甘醇二氯醚在碱性条件下对半胱氨酸巯基进行烷基化反应，成功地合成了多甘醇醚链桥联的半胱氨酸衍生物，醚化反应后，在高度稀释条件下与对叔丁基杯[4]芳烃二乙酰氯进行双功能基缩合反应成功地合成了新型的手性杯[4]含氮、硫杂冠醚，并利用〓H NMR、MS等谱图手段对其结构进行了表征。

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。