查询词典 pentylidene

It could be synthesized by a key intermediate 2-pentylidene cyclopentanone formed a condensation starting from cyclopentanone and n-valeraldehyde, followed by isomerization, Michael addition and a selective decarboxylation.

本文研究了以正戊醛和环戊酮为基本原料，经缩合反应、异构化反应、Michael加成反应和脱羧反应等制备二氢茉莉酮酸甲酯的化学合成方法和工艺。

The related reaction conditions and factors such as catalysis of some catalysts etc were discussed. In the procedures, 2-pentylidene cyclopentanone intermediate, which could be isomerizated into a 2-pentyl cyclopentenone under acidic conditions, was effectively prepared in the presence of a phase transfer promotor.

讨论了正戊醛和环戊酮在碱性条件下缩合生成2-亚戊基环戊酮的反应温度、碱浓度、相转移催化剂等因素对反应的影响。2-亚戊基环戊酮中间体化合物能在酸催化剂作用下，异构成2-戊基环戊烯酮，其中酸浓度和溶剂等参数对反应影响明显。

A synthesis of 2-pentylidene cyclopentanone starting from cyclopentanone and n-valeraldehyde through aldol condensation, followed by dehydration, was studied, and the yield reached 85.6%. 2-Pentenyl cyclopentanone was prepared in a yield of 95.0% from 2-pentylidene cyclopentanone with a hydrogenation methodology. Through Baeyer-villiger oxidation,δ-decalactone was synthesized in a yield of 63.9% from 2-pentenyl cyclopentanone with hydrogen peroxide.

研究了以正戊醛和环戊酮为起始原料，经羟醛缩合、脱水反应合成2-戊叉环戊酮，产率达到85.6%，2-戊叉环戊酮加氢制备2-戊基环戊酮，产率为95.0%，2-戊基环戊酮在双氧水作用下经Baeyer-villiger氧化重排反应合成δ-癸内酯，反应产率为63.9%，合成δ-癸内酯的总产率为52.0%，气相色谱分析纯度为98.7%。

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％。