728-15-4Relevant academic research and scientific papers
Preparation of α-(2,2-diphenylhydrazino)lactones and related compounds by radical cyclization: Use of glyoxylic acid hydrazone derivatives
Clive,Zhang,Subedi,Bouetard,Hiebert,Ewanuk
, p. 1233 - 1241 (2007/10/03)
Glyoxylic acid diphenylhydrazone (2a) and the corresponding O-benzyloxime (2b) are easily esterified in high yield by β-bromo alcohols. The resulting esters undergo radical cyclization to α-(2,2-diphenylhydrazino)- or α-[(phenylmethoxy)amino]lactones on treatment with tributyltin hydride. Esters for radical cyclization were also made using a β-(phenylseleno) alcohol and an enol ether. Several derivatives of glyoxylic acid were evaluated, but none was as effective as 2a or 2b. The imine 28 was prepared by an indirect route; it undergoes radical cyclization with displacement of the nitrogen substituent (28 → 30) so that an α-amino lactone can be generated by acid hydrolysis of the cyclization product.
Synthesis of C-glycosyl lactones and protected C-glycosyl amino acids: Use of radical cyclization
Zhang, Junhu,Clive, Derrick L. J.
, p. 770 - 779 (2007/10/03)
Protected carbohydrates 6a-13a, having one free hydroxyl and a phenylseleno group or halogen on the adjacent carbon, were condensed with (2,2-diphenylhydrazono)acetic acid (2); the resulting esters undergo radical cyclization to afford carbohydrates fused to a 2,2-diphenylhydrazino lactone unit (6c,d-13c,d). In suitable cases (9c,d) such carbohydrate lactones can be elaborated into C-glycosyl amino acids.
