A new convenient route to 2-oxoethoxycoumarins: key intermediates in the synthesis of natural products

A new synthetic route to coumarinyloxyaldehydes starting from hydroxycoumarins is presented; these compounds, useful intermediates in the preparation of natural products such as geiparvarin and psoralens, are now available in excellent yields with a simple workup procedure. Moreover the reported route has been applied to dihydroxycoumarins.