烯醇化作用

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。

It was shownthat, among the three possible tautomers; i.e., the keto-form and the two enol forms, and thecorresponding enol anion, only the enol form 31 was actually responsible for the singletoxygen reactions.

用核磁共振及从头算法研究了化合物12b和23a在甲醇和吡啶中的烯醇化作用，结果表明，在其三种互变异构体以及相应烯醇负离子中，只有烯醇式31是实际参与单重态氧反应的成份。

OBJECTIVE: To investigate the impact and brain protective effect of the application of oxygenised liquid during the surgery of hypertensive cerebral haemorrhage on the myelm basic protein.

目的：研究高血压脑出血术中应用携氧液对患者神经元特异性烯醇化酶的影响及脑保护作用。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。