2, 2-Dialkyl-3-dialkylamino-2, 3-dihydro-1H-naphtho [2, 1-b] pyrans were prepared from 2- naphthol, a secondary amine, and 3-hydroxy-2, 2-dialkylpropanal in the presence of a catalytic amount of p-toluenesulfonic acid. This one-pot reaction involves retro-aldol disintegration of 3-hydroxy-2, 2-dialkylpropanal followed by formation of a Mannich base intermediate from 2-naphthol, a secondary amine, and formaldehyde (retro-aldol product). ...