85951-66-2Relevant academic research and scientific papers
Photochemistry of Aminoketones. V. - Diastereoselective Synthesis of 3-Aryl-azetidin-3-ols via Photocyclization of Aryl-α-amidoalkyl-ketones
Fuhrmann, J.,Haupt, M.,Henning, H.-G.
, p. 177 - 186 (2007/10/02)
N-Acyl-azetidin-3-ols 3 and 4 are formed by diastereoselective cyclization of n,?*-excited N-benzyl-N-phenacyl-amides 1 and 2 in ether solution.Dependent on the nature of the p- and α-substituents of the phenacyl part and especially of the N-acylgroups in the amides 1 and 2 competing reactions occur, particularly the NORRISH II cleavage and an oxydative cleavage of the intermediate hydroxybiradicals A.N-Acylgroups with low energy barrier ΔG(excit.) of internal rotation favour the diastereoselective photocyclization by intramolecular interaction between the amide oxygen atom and the n,?*-CO-group in 1*, 2* and the OH group in the biradicals A, respectively.An intramolecular hydrogen bonding enables the N-tosyl-azetidinols 3 to rearrange to the N-tosylaminomethyl-benzhydryl-ketones 6 by 1-sensitized photoreaction.
