Please use this identifier to cite or link to this item:
標題: (I)以二氯甲烷及四氯化碳衍生的“類亞甲體”導引羰基烯化和烯類及酯類的三元環化(II)以1,1-二氯乙烯直接將酮丙烯化(III)(+)-Retronecine的合成研究
(I) CH2Cl2- and CCl4-Derived Carbenoid Equivalents in Carbonyl-Olefination and Cyclopropanation of Alkenes and Esters.(II) Direct Allenation of Ketones Using. H2C=CCl2(III) Synthetic Studies toward (+)-Retronecine.
作者: 簡敬庭
Chien, Ching-Ting
關鍵字: methylenation;四氯化鈦
出版社: 化學系所
第二部份的研究重點是探討1,1二氯乙烯(1,1-dichloroethylene)和双氯甲基醚(dichloromethyl methyl ether)與鈦-鎂双金屬所形成的類亞甲體和酮類進行丙二烯化反應(allenation)及甲烯醇醚化反應(methoxymethylenation),分別生成具備丙二烯和甲烯醇醚架構的化合物
第三部份是對於雜環生物鹼(+)-Retronecine的合成,利用實驗室中廉價的酒石酸L-(+)-tartaric acid當作起始物,三個步驟內把主要架構建立起來,同時具備正確的立體化學,不同於利用大環酯類水解的生物合成途逕,希望減少合成步驟及成本。

The thesis is divided into three parts.
In the first part, we wish to report protocols whereby TiCl4-Mg-promoted oxidative additions of CH2Cl2 and CCl4 can be directed to form methylene- and dichloromethylene carbenoids, respectively. With access to these systems, we explored the best conditions for the direct coupling of these methylene carbenoids with C=O and C=C double bonds. Not only can these ambiphilic carbenoids be directed to serve as highly nucleophilic methylenation equivalents in methylenation of ketones, aldehydes, and esters but they also seem to serve as highly electrophilic species in alken-cyclopropanations and ester-cyclopropanations.
To further demonstrate the synthetic utility of TiCl4-Mg bimetallic complex, in the second part, we concentrated on the allenation of ketones with vinylidene carbenoid derived from TiCl4-Mg-CH2=CCl2-THF and the methoxymethylenation of ketones with methoxymethylene carbenoid derived from TiCl4-Mg-(MeO)CHCl2-THF, leading to allene and vinyl methyl ether derivatives, respectively.
In the third part, we turned our attention to the asymmetric synthesis of (+)-Retronecine. To develop an efficient and practical route, we examined the use of L-(+)-tartaric acid as a cheap starting material. A facile construction of a [3.3.0] bicyclic framework, which might serve as a synthetic intermediate toward (+)-Retronecine, has been realized by virtue of the development of a three-step strategy involving coupling of (E)-2-bromo-4-amino-2-butenol with tartaric acid, silylation of diol, and application of the metal-halogen exchange to promote an intramolecular coupling of vinylbromide with imide. Further efforts will direct toward elaboration of this bicyclic intermediate into (+)-Retronecine.
Appears in Collections:化學系所

Show full item record

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.