3558-31-4Relevant academic research and scientific papers
Direct synthesis of unprotected α-amino acids via allylation of hydroxyglycine
Sugiura, Masaharu,Mori, Chieko,Hirano, Keiichi,Kobayashi, Shu
, p. 937 - 942 (2007/10/03)
Hydroxyglycine, the ammonia adduct of glyoxylic acid, was found to react with various allylboronates in the presence of triethylamine in methanol to give unprotected α-amino acids directly with high stereoselectivity. For instance, the reactions with (E)- and (Z)-crotylboronates afforded the corresponding anti- and syn-crotylated products (isoleucine and alloisoleucine after hydrogenation) with high diastereoselectivity, respectively. Interestingly, it was found that isomerization of the products (γ-adducts to α-adducts) occurred under the reaction conditions in some cases. Control experiments have suggested that the isomerization took place via 2-aza (or azonia) Cope rearrangement of imines derived from γ-adducts and glyoxylic acid.
