Straightforward Synthesis of 1-Amino-2,2-dialkylcyclopropanecarboxylic Acids via Selective Saponification of 2,2-Dialkylcyclopropane-1,1-dicarboxylic Esters and Curtius Rearrangement
摘要:
Selective monosaponification of dimethyl 2,2-dialkylcyclopropane-1,1l-dicarboxylic esters afforded the corresponding 2,2-dialkyl-1-(methoxycarbonyl)cyclopropane-1-carboxylic acids, which were rearranged with diphenyl phosphoroazidate via a modified Curtius-type reaction to give methyl 2,2-dialkyl-1-[N-(alkoxycarbonyl)amino]cyclopropanecarboxylic esters. Selective deprotection of the carbamate or methyl cyclopropanecarboxylic ester was worked out, giving rise to a whole variety of ACC analogues. Straightforward ways to 1-amino-2,2-dialkylcyclopropanecarboxylic acids (2,2-dialkyl-ACC's) were developed.
A novel method for the sterically shielded pyrrolidine nitroxides synthesis using donor–acceptor cyclopropanes
作者:Andrey I. Taratayko、Sophia Yu. Trakhinina、Konstantin A. Lomanovich、Igor A. Kirilyuk
DOI:10.1016/j.tetlet.2023.154546
日期:2023.6
shielded nitroxides were shown to demonstrate resistance to bioreduction. For this reason, they are attracting much interest as spin labels and probes for in-cell and in vivo EPR and NMR applications. Formal [3 + 2] cycloaddition reaction of donor–acceptor cyclopropanes with propionitrile provided 1-pyrrolines which were converted to the new sterically shielded achiral pyrrolidine nitroxides via several
TiCl<sub>4</sub> Promoted Formal [3 + 3] Cycloaddition of Cyclopropane 1,1-Diesters with Azides: Synthesis of Highly Functionalized Triazinines and Azetidines
A TiCl4 promoted formal [3 + 3] cycloaddition of cyclopropane 1,1-diesters with azides has been developed for the synthesis of highly functionalized triazinines. Both stoichiometric and substoichiometric versions of this reaction were accomplished dependent on the choice of solvent. It is noteworthy that the corresponding products could be easily converted to biologically important azetidines by simple thermolysis.
Synthesis of Cyclohexanes via [3 + 3] Hexannulation of Cyclopropanes and 2-Chloromethyl Allylsilanes
作者:Katarina Sapeta、Michael A. Kerr
DOI:10.1021/ol900457z
日期:2009.5.21
Lewis acid-assisted ring-opening/allylation of 1,1-cyclopropane diesters, followed by base-mediated ring closure, generates functionalized exo-methylenecyclohexanes in good yield. This two-step procedure is highlighted by expedient preparation of a pyrido[1,2-a]indole skeleton common to the chippiine class of Iboga indole alkaloids.
TfOH-Catalyzed Formal [3 + 2] Cycloaddition of Cyclopropane 1,1-Diesters with Nitriles
作者:Bo Cui、Jun Ren、Zhongwen Wang
DOI:10.1021/jo402383a
日期:2014.1.17
A triflic acid-catalyzed formal [3 + 2] cycloaddition of cyclopropane 1,1-diesters with nitriles was developed. This reaction was expeditious, and the scope of the substituents in both cyclopropanes and nitriles was broad. This supplies an efficient and practical method for the synthesis of 1-pyrrolines.