Enantioselective synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid ethyl ester (Vinyl-ACCA-OEt) by asymmetric phase-transfer catalyzed cyclopropanation of (E)-N-phenylmethyleneglycine ethyl ester was written by Belyk, Kevin M.;Xiang, Bangping;Bulger, Paul G.;Leonard, William R.;Balsells, Jaume;Yin, Jingjun;Chen, Cheng-yi. And the article was included in Organic Process Research & Development in 2010.Computed Properties of C37H37BrN2O This article mentions the following:
A concise asym. synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid Et ester, a key intermediate in the preparation of many hepatitis C virus inhibitors, is described. Stereoselective cyclopropanation of (E)-N-phenylmethyleneglycine Et ester was effected by treatment with trans-1,4-dibromo-2-butene in the presence of a catalytic amount of a chiral phase-transfer catalyst. Microscale high-throughput experimentation techniques were successfully used to identify a cinchonidine-derived catalyst that provided (1R,2S)-1-(E)-N-phenylmethyleneamino-2-vinylcyclopropanecarboxylic acid Et ester in up to 84% ee. This was translated to a lab scale process to attain 78% yield and 77.4% ee. Chiral purity upgrade and isolation of the ester was accomplished via preparatory supercritical fluid chromatog. followed by crystallization of the ester as its tosylate salt. The improved synthesis described herein represents a potentially more economical preparation of this valuable intermediate. In the experiment, the researchers used many compounds, for example, (1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide (cas: 200132-54-3Computed Properties of C37H37BrN2O).
(1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide (cas: 200132-54-3) belongs to quinuclidine derivatives. In alkane solvents quinuclidine is a Lewis base that forms adducts with a variety of Lewis acids. Quinuclidine derivatives can also be formed conveniently by introducing substituents into the quinuclidine ring, but the scope of this method is rather limited by the available source of starting materials.Computed Properties of C37H37BrN2O
Referemce:
Quinuclidine – Wikipedia,
Quinuclidine | C7H13N | ChemSpider