A concise route to beta-Cyclopropyl amino acids utilizing 1,2-dioxines and stabilized phosphonate nucleophiles
Thomas D Avery1, Ben W Greatrex, Daniel Sejer Pedersen
1Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
Abstract:
1,2-Dioxines react with glycine-derived phosphonate nucleophiles via a multistep cascade reaction to give beta-cyclopropyl amino acid derivatives in good yield with excellent control of the cyclopropane stereocentres. The cyclopropyl ketones were oxidized to the corresponding carboxylic esters using Baeyer-Villiger conditions. Standard deprotection protocols produced a series of known beta-cyclopropyl amino acids that are selective and potent agonists or antagonists of the metabotropic glutamate receptors in excellent yields.
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