Synthesis of 1,3,4-Oxadiazoles from Carboxylic Hydrazides and of 1,2-Oxazin-6-ones from α-(Hydroxyimino)carboxylic Esters with Keteneylidene Triphenylphosphorane
Synthesis of 1,3,4-Oxadiazoles from Carboxylic Hydrazides and of 1,2-Oxazin-6-ones from α-(Hydroxyimino)carboxylic Esters with Keteneylidene Triphenylphosphorane
作者:Jonas Löffler、Rainer Schobert
DOI:10.1055/s-1997-766
日期:1997.3
In a one-pot procedure 1,3,4-oxadiazoles 8 are prepared from carboxylic hydrazides 2 and keteneylidene triphenylphosphorane 1 via an untypical intermolecular Wittig olefination of a carbamate type carbonyl group. Under similar conditions, reaction of 1 and α-(hydroxyimino) carboxylic esters 9 furnishes 1,2-oxazin-6-ones 11 by a different process including an intramolecular olefination step.