| Abstract
| - Previously, a method for the stereoselective synthesis of β-lactams, starting from 2H-Δ2-thiazolinesand Meldrum's acid derivatives, has been reported from our laboratory. We now report a new methodfor the synthesis of optically active, highly substituted ring-fused 2-pyridinones. This was discoveredwhen 2-alkyl-Δ2-thiazolines and Meldrum's acid derivatives were treated with HCl(g) in benzeneat 5 → 78 °C. Further refinement of the synthetic protocol revealed that use of 1,2-dichloroethaneas solvent at 0 → 64 °C led to the desired 2-pyridinones in good yields and with excellentenantioselectivity. Use of these conditions allowed preparation of 2-pyridinones from several differentΔ2-thiazolines and Meldrum's acid derivatives and may be a general route to 2-pyridinones.
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