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

Abstract

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.

Enantioselective and collective total synthesis of pentacyclic 19-nor-clerodanes

“…2-Pyrone-based Diels–Alder reactions are a prominent method for the construction of six-membered carbocycles. 14 Recently, catalytic asymmetric inverse-electron-demand Diels–Alder (IEDDA) reactions of 2-pyrones have attracted increasing attention owing to their great potential in the synthesis of bioactive natural products, which was demonstrated by Markó, 15 Posner, 16 Gademann, 17 de la Torre 18 and our group. 19 In 2020, our group has developed an efficient method for the construction of densely functionalized cis -decalin scaffolds by ytterbium-catalyzed asymmetric IEDDA reactions of 2-pyrones and then applied it to the total synthesis of terpenoids 4-amorphen-11-ol and cis -crotonin.…”