The first direct transition metal-free access to 3,6-disubstituted α-pyrones from α-chloro aldehydes and β-tosyl enones is reported. The reactions proceed via the Michael addition/lactonization/elimination cascade. The regioselective addition of NHC-bound enolates/homoenolates to the enones bearing a bulkier functionality such as tosyl group at the β-position has remained challenging. The 3,6-disubstituted α-pyrones could be converted to valuable products such as 1,2,3,4-tetrasubstituted benzenes, 1,4-disubstituted naphthalenes as well as anthracenes and 6,13-disubstituted dihydro-ethenopentacenes in a simple operation.

中文翻译：

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卡宾催化通过迈克尔加成/内酯化/消除级联获得 3,6-二取代 α-吡喃酮

报道了第一个从α-氯醛和β-甲苯磺酰基烯酮直接无过渡金属获得 3,6-二取代α-吡喃酮的方法。反应通过迈克尔加成/内酯化/消除级联进行。将 NHC 结合的烯醇化物/同烯醇化物区域选择性地添加到具有更大官能团（例如β位的甲苯磺酰基）的烯酮中仍然具有挑战性。3,6-二取代的α-吡喃酮可以通过简单的方法转化为有价值的产品，如1,2,3,4-四取代苯、1,4-二取代萘以及蒽和6,13-​​二取代二氢乙烯并五苯。手术。