Regioselective functionalization of pyrones: Facile synthesis of 6-styrylpyrones via KHMDS-mediated aldol condensation

Herein, we disclose our efforts directed toward the synthesis of the kavalactone-based natural product penstyrylpyrone and other related 4-OMe-2-pyrones possessing diverse substituents at the 3-, 5-, and 7-positions. Further, a facile approach to access 6-styrylpyrones via the KHMDS-mediated regioselective aldol condensation of 2-pyrones is described with moderate substrate scope and good to high yields (58- 80%). The utility of this methodology was exemplified by the stereoselective construction of desmethoxyyangonin, asnipyrone A, and asnipyrone B. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This article presents efforts towards synthesizing the kavalactone-based natural product penstyrylpyrone and related 4-OMe-2-pyrones with diverse substituents at the 3-, 5-, and 7-positions. Additionally, a simple approach for accessing 6-styrylpyrones through KHMDS-mediated regioselective aldol condensation of 2-pyrones is described, showing moderate substrate scope and good to high yields. The utility of this methodology is exemplified by the stereoselective construction of desmethoxyyangonin, asnipyrone A, and asnipyrone B.