5,6-Dihydro-4H-benzofuran-7,7-dicarboxylic acid dimethyl ester

2-Oxo-3-(2-oxo-ethyl)-cyclohexane-1,1-dicarboxylic acid dimethyl ester

(R)-7-Hydroxymethyl-4,5,6,7-tetrahydro-benzofuran-7-carboxylic acid methyl ester

(7R)-7-methoxycarbonyl-4,5,6,7-tetrahydrobenzofuran-7-carboxylic acid