Base‐Catalyzed Condensation of 2‐Hydroxybenzaldehydes with α,β‐Unsaturated Aldehydes – Scope and Limitations

The base‐catalyzed condensation of α,β‐unsaturated carbonyl compounds with 2‐hydroxybenzaldehydes yielding tetrahydroxanthones and dihydrobenzopyrans has been investigated. A novel access to highly functionalized dihydrobenzopyrans via a mild generation of the dienol of senecialdehyde and subsequent conjugated aldol reaction has been reported.