Asymmetric synthesis of trans-4,5-dioxygenated cyclopentenone derivatives by organocatalyzed rearrangement of pyranones and enzymatic dynamic kinetic resolution

作者：Nunes Joao P M; Veiros Luis F; Vaz Pedro D; Afonso Carlos A M^*; Caddick Stephen

来源：Tetrahedron, 2011, 67(15): 2779-2787.

DOI：10.1016/j.tet.2011.02.018

• Organocatalysis
• Dynamic kinetic resolution
• Lipase-catalyzed acylation
• Pyranone rearrangement
• trans-Dioxygenated cyclopentenone

Dioxygenated cyclopentenones are versatile building blocks for the synthesis of several natural products. Herein we report a direct asymmetric synthesis of trans-4,5-dioxygenated cyclopentenone derivatives through base-catalyzed rearrangement of pyranones followed by dynamic kinetic resolution. Milder conditions than previously reported for this rearrangement have been found regarding amine base catalysis, solvent and temperature effects. All data supports a mechanism involving cyclization of an intermediate formed by electrocyclic ring opening of a pyranone-derived enol. We have developed conditions for asymmetric synthesis of trans-4-tert-butoxy-5-hydroxycyclopent-2-enone, in 81% yield and 95% ee, and analogous dioxygenated cyclopentenones, via a lipase induced dynamic kinetic resolution.

• 出版日期2011-4-15