(R)-2-Methoxycarbonylmethyl-2-methyl-1-thiosuccinimide

(3R,4E)-9-tert-Butoxycarbonyl-5-cyano-8-(2-methoxycarbonylethyl)-3-methoxycarbonylmethyl-3,7-dimethyl-2,3-dihydrodipyrrin-1(10H)-one

methyl 5-methyl-4,6-dioxoheptanoate

5-acetoxymethyl-3-(2-methoxycarbonyl-ethyl)-4-methyl-pyrrole-2-carboxylic acid tert-butyl ester

tert-Butyl 3-(2-methoxycarbonylethyl)-4,5-dimethylpyrrole-2-carboxylate