Thermal [4 + 2] Cycloadditions of 3-Acetyl-, 3-Carbamoyl-, and 3-Ethoxycarbonyl-Coumarins with 2,3-Dimethyl-1,3-butadiene under Solventless Conditions: A Structural Study

Molecules

关键词: coumarins;    Diels-Alder adducts;    solventless reactions;    6a,7,7a,8a,9,9ahexahydro-7a,8a-dimethyl-6-oxo-6H-5,8-dioxacyclopropa[b]phenantrenes;   

DOI  :  10.3390/molecules15031513

来源: DOAJ

【 摘 要 】

The thermal [4+2] cycloadditions of 3-acetyl-, 3-carbamoyl, and 3-ethoxycarbonylcoumarins with 2,3-dimethyl-1,3-butadiene under solvent free conditions are reported, as well as the epoxidation reactions of some adducts. Discussion is focused on the structural features of the Diels-Alder adducts and their epoxides, based upon NMR, X-ray, and mass spectral data, and supported by ab initio theoretical calculations.

【 授权许可】

Unknown