Aldol condensation of 6-alkoxy-2,2-dimethylchroman-4-ones with substituted benzaldehydes using tetramethylorthosilicate and potassium fluoride

The aldol condensation of 6-alkoxy-2,2-dimethylchromanones 1 or 2 with substituted benzaldehydes in the presence of tetramethylorthosilicate and potassium fluoride affords 6-alkoxy-3 -benzylidene-2,2-dimethylchromanones 5-10 while other conventional methods were unsuccessful.