Synthesis of 1-amino-2,2-dialkylcyclopropanecarboxylic acids from β-chloroaldimines
摘要:
A variety of hydrogen cyanide adducts of beta-chloroaldimines using acetone cyanohydrin were prepared. The reactive behaviour of these alpha-amino-gamma-chloronitriles towards bases was investigated with the aim to generate 1-aminocyclopropanecarbonitriles, which are precursors for the potentially plant growth regulating 1-aminocyclopropanecarboxylic acids. The synthesis of 1-amino-2,2-dimethylcyclopropanecarboxylic acid (= 2,3-methanovaline) by a reaction sequence involving addition of hydrogen cyanide across beta-chloroaldimines, ring closure to functionalized cyclopropanes and acidic hydrolysis was accomplished. Alternatively the hydrogen cyanide adducts of beta-chloroaldimines were converted into alpha-(N-benzylidene)amino-gamma-chloronitriles, which were ring closed with base and hydrolyzed to afford 1-amino-2,2-dialkylcyclopropanecarbonitriles, the latter serving again as substrates for the hydrolytic conversion into the corresponding 1-amino-2,2-dialkylcyclopropanecarboxylic acids (exemplified for 1-amino-2,2-dimethylcyclopropanecarboxylic acid).
A novel synthesis of 2-cyano-3,3-dimethylazetidines
作者:Paul Sulmon、Norbert De Kimpe、Niceas Schamp
DOI:10.1039/c39850000715
日期:——
A new route to 2-cyano-3,3-dimethylazetidines has been developed by reaction of β-chloroimines with potassium cyanide in methanol which involves nucleophilic addition and subsequent intramolecular nucleophilic substitution.
Synthesis and reactivity of 3-(2-chloroalkyl)-2,2-dihaloaziridines
作者:Ekaterina Yu. Shinkevich、Kourosch Abbaspour Tehrani、Alexander F. Khlebnikov、Mikhail S. Novikov
DOI:10.1016/j.tet.2008.05.121
日期:2008.8
3-(2-Chloroalkyl)-2,2-dihaloaziridines were synthesized via cycloaddition of dihalocarbenes to the CN double bond of β-chloroimines. Under the action of Lewis acids or HCl, N–C3 bond cleavage occurred, giving rise to N-substituted 2,4-dichloro-3,3-dimethylbutanamides, which were further converted to 3-chloropyrrolidin-2-ones under alkaline conditions. When 2,2-dichloro-3-(2-chloro-1,1-dimethylethy
A new method for the preparation of 2,2-dialkylcyclopropylamines
作者:Paul Sulmon、Norbert De Kimpe、Niceas Schamp
DOI:10.1039/c39860001677
日期:——
2,2-Dialkylcyclopropylamines have been prepared by a new synthetic method involving base-induced cyclization of β-chloroimines and subsequent hydrolysis.