Activation of <i>o</i>-Propargyl Alcohol Benzaldehydes under Acetalization Conditions for Intramolecular Electrophile Intercepted Meyer–Schuster Rearrangement
intercepted Meyer–Schuster (M–S) rearrangement under acetalization conditions using trimethyl orthoformate (TMOF). The in situ formed acetal transfers the methoxy group intramolecularly to generate the M–S intermediate in even less reactive substrates, and the formed oxocarbenium ion makes the carbonyl more electrophilic for an effective intramolecular trapping of the M–S intermediate to furnish the indanone