2-benzyloxymethyl-1-(4-methoxy-benzyl)-3-methyl-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylic acid methyl ester

6-benzyloxymethyl-5-(4-methoxy-benzyl)-2,6a-dimethyl-4-oxo-hexahydro-pyrrolo[3,4-d]isoxazole-6-carboxylic acid methyl ester