A modular approach to mitosene-like scaffolds via an aryne-imino ester annulation sequence leading to MeO-group transposition.

Mitomycins and mitosenes are structurally complex quinone-containing natural products whose synthesis remains challenging. We report a metal-free, scalable aryne-imino ester annulation followed by MeO-group transposition, generating a quaternary carbon center to access mitosene-like scaffolds under mild conditions, avoiding protecting-group manipulations. The resulting intermediates are suitable for late-stage diversification toward mitomycin natural products and analogues.