Versiatile Methylenecyclopentane Annulations of Unactivated and Electron-Rich Olefins with cyclopropanedicarboxylates

Article abstract of DOI:10.1021/jo00087a015

<(Trimethylsilyl)methylene>cyclopropanedicarboxylates 8a-c are readily available from the cyclopropanation of the silylallenes 7a-c with dimethyl diazomalonate.The free-radical mediated methylenecyclopentane annulations of unactivated and electron-rich alkenes with 8a-c proceed in high yield.The product vinylsilanes are set up for diverse secondary conversions, making annulations with 8a-c highly versatile in the synthesis of cyclopentanes.