Chromone Studies. Part 14.1 Unprecedented Dimerisation of Chromone-3-Carbaldehyde-Derived Baylis–Hillman Adducts

Abstract

1,4-Diazabicyclo[2.2.2]octane (DABCO)-catalysed Baylis-Hillman reactions of selected chromone-3-carbaldehydes with methyl acrylate have been shown to afford mixtures of the expected Baylis-Hillman products and unprecedented dimeric derivatives. The Baylis–Hillman products, on heating at 80°C in the presence of DABCO, are converted to the corresponding dimers, the structures of which have been unambiguously established by NMR and X-ray crystallographic analysis. Electron-impact and electrospray MS data for the dimeric systems are discussed.