6-(5-(甲氧基羰基)吡啶-3-基)-4-氧代螺[苯并二氢吡喃-2,4-哌啶]-1-羧酸叔丁酯

methyl 5-(3-methylphenyl)pyridine-3-carboxylate

methyl 5-(2-methylphenyl)pyridine-3-carboxylate

methyl 5-(2-methoxyphenyl)pyridine-3-carboxylate

methyl 5-(furan-2-yl)pyridine-3-carboxylate