SmI2-Mediated Cross-Coupling of Nitrones with β-Silyl Acrylates: Synthesis of (+)-Australine

The SmI2-mediated cross-coupling of nitrones with beta-silyl-alpha,beta-unsaturated esters, followed by zinc reduction, allows an efficient and highly diastereoselective preparation of beta-silyl lactams, which are precursors of beta-hydroxy lactams through Tamao-Fleming oxidation. By applying the method to a cyclic, carbohydrate-derived nitrone, a new synthesis of (+)-australine has been realized in only 11 steps and in 21% overall yield from L-xylose.