Oxime Resin

Oxime resins have been used for the synthesis of carboxylic acid derivatives by nucleolytic cleavage. Carboxylic acids can be attached to the resin using DCC method. As the oxime linkage is not completely stable to TFA, the use of 25% TFA in DCM is recommended for removal of Boc groups. Caboxamides, esters, and enantiopure hydroxamic acids have been synthesized with the resin and using hydrazine and amines, amino acid esters, and hydroxylamine, respectively, as cleavage agents. N-Methyloctadepsipeptides attached to the resin were cyclized by heating them in refuxing ethyl acetate for 2 days to give cyclodepsipeptide PF1022A analogues