107341-60-6Relevant articles and documents
The Influence of Steric and Electronic Effects on the Stability of Aldonitrones and on their Conversion into Isoxazolidines
Aurich, Hans Guenter,Eidel, Joachim,Schmidt, Michael
, p. 18 - 35 (2007/10/02)
The nitrones 3Aa-Ai were isolated from the reaction of tert-butylhydroxylamine (1A) with aldehydes 2a-i. 1B-D react in an analogous manner. 3Aa-Ac convert slowly into the isoxazolidines 5Aa-Ac, whereas 3Ad-Ai do not.Phenylhydroxylamine (1F) reacts with 2a-d to yield 5Fa-Fd, likewise compounds 5Ea, Ed and the rearranged product 5Ub are formed from 1E.Reaction of 1F and 2f-h, however, yields the nitrones 3Ff-Fh. 3Ff exists in an equilibrium with a dimer of structure 6. - Compounds 5Aa-Ac were found to undergo cycloreversion to give the nitrones 3 in solution, whereas 5Fa-Fd as well as 5Ea, Ub, and Ed did not.There is a steady decrease in the tendency for cycloreversion in the order 5Ab > 5Bb > 5Cb, however, the degree of cycloreversion is also solvent-dependent.Acyclic compounds 7 were found to be intermediates in the conversion of 5Aa and Bb into the corresponding nitrones.Compound 9, formed from 1A and acrolein (8), does not decompose to yield its components 3Aa and 11.The influence of electronic and steric effects on the relative stability of the nitrones 3 and isoxazolidines 5 is discussed.
