Practical, chromatography-free syntheses of 5-lipoxygenase inhibitor MK-0633 p- toluenesulfonate (1) are described. The first route used an asymmetric zincate addition to ethyl 2, 2, 2-trifluoropyruvate followed by 1, 3, 4-oxadiazole formation and reductive amination as key steps. An improved second route features an inexpensive diastereomeric salt resolution of vinyl hydroxy-acid 22 followed by a robust end-game featuring a through- ...
![4-(4-fluorophenyl)-7-[[[5-[(2S)-1,1,1-trifluoro-2-hydroxybutan-2-yl]-1,3,4-oxadiazol-2-yl]amino]methyl]chromen-2-one Structure](https://image.chemsrc.com/caspic/054/910656-27-8.png)