Abstract A “stop-and-flow” strategy was developed for the chemoselective dioxygenation of alkenes with a PIFA-initiated cyclization. This method is conceived for the desymmetrization of seco-diene, and a series of substituted 5-hydroxymethyl-γ-lactones were constructed after hydrolysis. This strategy also differentiates terminally substituted alkenes and constitutes a potentially novel synthetic approach for the efficient synthesis toward velbanamine.
![2-[3,5-bis(4-methoxyphenyl)-4,5-dihydropyrazol-1-yl]-4-(4-fluorophenyl)-1,3-thiazole hydrobromide结构式](https://image.chemsrc.com/caspic/118/5309-50-2.png)
