查询词典 lactonization

A one-pot chemoselective reduction and lactonization of(4S,5R)-hemiesters was carried out to afford high-yielding(3aS,6aR)-lactone,a key chiral building block for the biotin synthesis. One-step introduction of carboxybutyl chain onto(3aS,6aR)-thiolactone was reached upon treatment of zinc reagent 25 in the presence of nanopalladium via an improved Fukuyama coupling under mild reaction conditions.

在侧链引入过程中，采用纳米钯LDH-Pd~0为催化剂以改进的Fukuyama偶联反应一步高效地引入-生物素五碳羧酸侧链，紧接着创造性地以离子氢化的方式建立了-生物素的第三个手性中心。

Chiral centers of C5 and C8 are directly constructed in the key step of the diastereoselective propargylation from D--tartrate. The methylation and subsequent methoxycarbonylation result in desymmetrization of the terminal dialkynes. The α,β-unsaturated δ-lactone is synthesized after partial hydrogenation and lactonization.

由非天然酒石酸出发，利用双向非对映选择性的炔丙基化反应，在一步反应中同时构建C5和C8手性中心；然后通过末端炔基的甲基化、甲酯基化，延长碳链并对分子去对称化；内酯化得到关键中间体α，β-不饱和六元内酯，再经多步反应转化得到8-epi--Boronolide。

Through diazotization-lactonization,esterification, reduction, ether formation and double bond formation,the optically active--γ-benzyloxy methy-γ-butanolideXXIII and--γ-benzyloxy mothy-γ- butenolideXXV were preparedstarting from L-glutamic acid.

本论文采用易得的L-谷氨酸为原料，经重氮化-内酯化、酯化、还原、醚化和形成双键五步反应，合成了光学活性的化合物XXIII和XXV(Scheme 6，P.63)。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。