192210-08-5Relevant articles and documents
A convenient synthesis of (E)-4-alkoxy-2-amino-3-butenoic acid derivatives
Kobayashi, Kazuhiro,Irisawa, Susumu,Akamatsu, Hideki,Takahashi, Masaki,Kitamura, Taichi,Tanmatsu, Miyuki,Morikawa, Osamu,Konishi, Hisatoshi
, p. 2307 - 2313 (2007/10/03)
(E)-4-Alkoxy-2-formylamino-3-butenoic acid esters have been prepared in two steps from 3-alkoxy-1-isocyanopropenes. The method is based on the reaction of 3-alkoxy-1-isocyano-1-lithiopropenes, which can be generated by the treatment of 3-alkoxy-1-isocyanopropenes with LDA in THF at -78 °C, with alkyl chlorocarbonates, affording 4-alkoxy-2-isocyano-3-butenoates. These isocyano esters have been easily transformed into the corresponding formylamino esters by treating with concd HCl in Et2O at - 20 °C. Subsequently, the introduction of a substituent into the 2-position has been achieved by ethoxycarbonylation with ethyl chlorocarbonate, followed by alkylation with alkyl halides by using hexamethylphosphoric triamide (HMPA) as a co-solvent. The resulting alkylated isocyano 3-butenoates have been similarly hydrolyzed with concd HCl to the corresponding 2-formylamino-3- butenoates.
