Total Synthesis of (–)-Rosmarinecine by Intramolecular Cycloaddition of (S)-Malic Acid Derived Pyrroline N-Oxide

Straightforward total syntheses of (-)-rosmarinecine have been achieved from L-malic acid derived pyrroline N-oxides by two novel useful cascade processes, which join the family of domino reactions. Both strategies, which furnished the target alkaloid in enantioenriched and enantiopure forms, respectively, allow complete control of configuration at all the three newly created contiguous stereogenic centers.