Aluminum amalgam nitriles

The indolyl nitro compound (98) was converted to the corresponding nitrile oxide, which cyclized to afford an inseparable mixture of isoxazolidines (99) and (100 Scheme 2S).46 These were acetylated and the THP group replaced by a mesyl group at which point the desired 3-isomer could be separated. Elimination via a selenide intermediate provided the alkenylisoxazoline (101), which was converted to an isoxazolinium salt and reduced with LAH to give an N-methylisoxazolidine. Reductive cleavage with aluminum amalgam provided (+)-paliclavine. 

---