α-Alkoxystannanes as masked oxonium ions: application to the synthesis of furo[2,3-b]pyrans

α-Alkoxystannanes undergo oxidation upon treatment with cerium ammonium nitrate generating oxonium ions, which can be trapped in an intramolecular fashion affording furo[2,3-b]pyrans.

α-Alkoxystannanes undergo oxidation to oxonium ions using CAN, which on intramolecular capture, provides ready access to furo[2,3-b]pyrans