title: Conformationally restricted nonchiral pipecolic acid analogues.
abstract: Practical syntheses of 2-azabicyclo[3.1.1]heptane-1-carboxylic (2,4-methanopipecolic), 2-azabicyclo[2.2.2]octane-1-carboxylic (2,5-ethanopipecolic), and 9-azabicyclo[3.3.1]nonane-1-carboxylic (2,6-propanopipecolic) acids are reported. The synthetic schemes are short (five, seven, and five steps, respectively) and result in reasonably high yields of the title compounds. The key step in the syntheses is the tandem Strecker reaction and intramolecular nucleophilic cyclization of ketones possessing a leaving group at the delta-position.
authors.affiliation: Department of Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska Street 64, Kyiv 01033, Ukraine.
authors.forename: Dmytro S
authors.initials: DS
authors.lastname: Radchenko
authors.forename: Nataliya
authors.initials: N
authors.lastname: Kopylova
authors.forename: Oleksandr O
authors.initials: OO
authors.lastname: Grygorenko
authors.forename: Igor V
authors.initials: IV
authors.lastname: Komarov
mesh_terms: D003500:Cyclization; D007659:Ketones / Q000737:chemistry; D008968:Molecular Conformation; D010875:Pipecolic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007659:Ketones; D010875:Pipecolic Acids