93625-04-8Relevant articles and documents
Ouverture d'epoxydes par le N-hydroxycarbamates de methyle; syntheses de tetrahydrodioxazine-1,4,2 ones-3 et de carbomethoxy-2 tetrahydrodioxazines-1,4,2
Fruchier, Alain,Moragues, Veronique,Petrus, Clement,Petrus, Francoise
, p. 173 - 182 (2007/10/02)
The ring opening of epoxides in a basic medium by methyl N-hydroxycarbamate reacting as an N-protected hydroxylamine by its oxanion CH3O-CO-NHO(-) gives the corresponding carbomethoxyaminoxyalcohols 2.These compounds can react further to give: N,O-di(hydroxy-2' alkyl)hydroxylamines 3 by opening of a second epoxide molecule; diols RCH(OH)CH2OH 4 by rupture in basic medium of the N-O linkage of 2; 1,4,2-tetrahydrodioxazine-3 ones 5 by intramolecular cyclisation of 2.The oxanion CH3O-CO-NHO(-) attacks the primary carbon of the epoxide except in the case of epoxystyrene where as minor attack on the secondary carbon is also observed.The cyclization of carbomethoxyaminoxyalcohols 2 with aldehydes or their corresponding acetals in the presence of paratoluene sulfonic acid is a rapid and easy two step synthesis of 2-carbomethoxy-tetrahydrodioxazines-1,4,2 8.