Highly regioselective deprotonation of the title compounds is achieved by working with lithium-amide bases of different steric requirement. The effect of a 5-alkoxymethyl group in theΔ2-isoxazoline ring on both the sense and the extent of the stereoselectivity observed in the reaction of C4-anion with electrophiles is discussed.
![4-methyl-2-oxo-5-[(4-oxo-3-propyl-2-sulfanylidene-1,3-thiazolidin-5-ylidene)methyl]-1-propyl-6-pyrrolidin-1-ylpyridine-3-carbonitrile Structure](https://image.chemsrc.com/caspic/127/7064-06-4.png)
