A Regio‐ and Diastereoselective Stille Coupling/Intramolecular Diels–Alder Cascade for the Generation of Fused Pyridines and Application in the Synthesis of (+)‐Lycopladine A and (−)‐Lycoposerramine R

2‐Pyrones with a chiral branched allylic silyl ether substituent underwent intramolecular Diels–Alder reactions with remarkably high π‐facial‐ and endo‐selectivities. The resulting diastereomerically and enantiomerically pure cycloadducts were transformed into the natural products (+)‐lycopladine A and (−)‐lycoposerramine R. Highly efficient asymmetric intramolecular Diels–Alder reactions of 3‐substituted 2‐pyrones were combined with C3‐selective Stille cross‐coupling reactions in a tandem fashion. The resulting diastereomerically and enantiomerically pure cycloadducts were successfully converted into (+)‐lycopladine A and lycoposerramine R.