乙烷基

ABSTRACT: In the presence of sodium t-butoxide and DMSO,ethyl 2-oxocyclopentanecarboxylate was subjected to C-alkylation with 2-(4-bromomethylphenyl)propanoic acid with high regioselectivity to give 2-［4-(1-ethoxycarbonyl-2-oxo-1-cyclopentanylmethyl)phenyl］propanoic acid (4) which was followed by hydrolysis,decarboxylation and salt formation to afford loxoprofen sodium in about 72% overall yield.

在叔丁醇钠和二甲基亚砜的存在下，2-丙酸对2-乙氧羰基环戊酮进行C-烷基化，再经水解脱羧，成盐即得洛索洛芬钠，以2-丙酸计算，总收率为72%。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。