The photohydrolysis of furans

The defossilization of the chemical industry is accelerated by the shift from petroleum- to biomass-based feedstocks. At the center stage are bioderived furans, from which valuable platform chemicals can be obtained exclusively through oxidative or reductive processes. By contrast, the conceptually straightforward redox-neutral hydrolysis of furan to succinaldehyde and 2-substituted furans to 1,4-ketoaldehydes has been considered unfeasible owing to their endergonicity and polymerization side reactivity. In this work, we report the realization of this uphill furan hydrolysis through photocatalysis involving a highly strained, 10-membered 1,6-dioxecine intermediate. Succinaldehyde, as well as 1,4-ketoaldehydes, can be directly obtained from furans. Additionally, furfural derivatives undergo redox-enhanced Piancatelli rearrangements, accessing antimicrobial natural products (±)-Terrein and (±)-epi-Pentenomycins. The methodology was applied to the redox-neutral production of common industrial fine chemicals, avoiding wasteful redox detours typical in biomass-based synthesis.