O-Nitrobenzhydryl esters

Dinitrobenzenesulphenyl and o-nitrobenzhydryl esters are carboxyl protective groups which can be removed by photolysis under mild and completely neutral conditions and give the carboxylic acid in high yield (85—98%) [47, 124]. The major by-product in the decomposition of the 2,4-dinitrobenzene-sulphenyl ester (45) is the sulphide (47) formed by electrophilic attack of the cation (46) on the solvent. o-Nitrosobenzo-phenone (48) is formed as the by-product in the decomposition of the nitrobenzhydryl ester. 

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