The one‐pot sequential synthesis of (−)‐oseltamivir has been achieved without evaporation or solvent exchange in 36 % yield over seven reactions. The key step was the asymmetric Michael reaction of pentan‐3‐yloxyacetaldehyde with (Z)‐N‐2‐nitroethenylacetamide, catalyzed by a diphenylprolinolsilylether. The use of a bulky O‐silyl‐substituteddiphenylprolinol catalyst, chlorobenzene as a solvent, and