A series of 2-substituted and 2, 2-disubstituted 1, 3-benzodioxoles have been synthesised by reaction of catechol and pyrogallol with corresponding aldehydes and ketones catalysed by montmorillonite KSF or K-10. The reactions are completed within 2.7–24 h to give satisfactory yields. Ketones give better yields than aldehydes, although highly sterically hindered ketones and diaryl ketones fail to react at all.
