33026-27-6Relevant articles and documents
Efficient Transfer of Chelating Amides into Different Types of Esters and Lactones
Jakob, Uwe,Mundinger, Stephan,Bannwarth, Willi
, p. 6963 - 6974 (2016/02/18)
We describe a general and versatile approach for the conversion of carboxylic acid amides into their corresponding esters despite the fact that the former are thermodynamically more stable. The transformations are mediated by the coordination of CuI by a chelating entity. The resulting weakening of the amide bond allows for nucleophilic attack by alcoholic hydroxyl functions. The principle is demonstrated for a wide variety of transformations, leading to different kinds of esters and lactones. Due to their high resonance energy, amides are generally very stable towards solvolysis. However, bispicolylamides can be activated for alcoholysis by an unusual metal coordination involving the electron pair of the amide nitrogen. Herein, we widened the scope of the reaction by transforming the amides into a range of esters and lactones.
THE NORRISH TYPE II PHOTOREACTION OF BENZOYLVALERATES. STEREOCHEMICAL CONTROL IN 1,4-BIRADICAL CYCLIZATION
Hasegawa, Tadashi,Arata, Yoshiaki,Kageyama, Akihiko
, p. 1995 - 1996 (2007/10/02)
The δ- and β-oxoester 1 and 5 underwent the Type II photoreaction to give the stereoisomeric cyclobutanol 2 and 6, respectively; the ethoxycarbonyl group in the esters determines the stereochemistry of 1,4-biradical cyclization.