Cyclization of the benzoylpiperidine in lead compound 2 generated a series of novel and highly potent spiropiperidine-based stearoyl-CoA desaturase (SCD)-1 inhibitors. Among them, 1′-{6-[5-(pyridin-3-ylmethyl)-1, 3, 4-oxadiazol-2-yl] pyridazin-3-yl}-5-(trifluoromethyl)- 3, 4-dihydrospiro [chromene-2, 4′-piperidine](19) demonstrated the most powerful inhibitory activity against SCD-1, not only in vitro but also in vivo (C57BL/6J mice). With ...