Sequential Ketene Generation from Dioxane-4,6-dione-keto-dioxinones for the Synthesis of Terpenoid Resorcylates
作者:Daniel C. Elliott、Tsz-Kan Ma、Aymane Selmani、Rosa Cookson、Philip J. Parsons、Anthony G. M. Barrett
DOI:10.1021/acs.orglett.6b00533
日期:2016.4.15
Trapping of the ketene generated from the thermolysis of 2-methyl-2-phenyl-1,3-dioxane-4,6-dione-keto-dioxinone at 50 °C with primary, secondary, or tertiary alcohols gave the corresponding dioxinone β-keto-esters in good yield under neutral conditions. These intermediates were converted by palladium(0)-catalyzed decarboxylative allyl migration and aromatization into the corresponding β-resorcylates
The synthesis of 3,5-dioxoheptanedioic acid derivatives based on the reaction of ketene with malonyl chloride was developed. Resulting diketones were subjected to Ru–(S)-BINAP-catalyzed asymmetric hydrogenation. The products were transformed into enantiomericallypure 3,5-substituted-δ-valerolactones.