Efficient condensation of p-substituted phenols, p-thiocresol and 2,7-dihydroxyn aphthalene with malonaldehyde tetramethyl acetal in trifluoroacetic acid

Condensation reactions of malonaldehyde tetramethyl acetal with p-substitut ed phenol derivatives and p-thiocresol have been carried out in trifluoroac etic acid and the corresponding methano-dibenzo[1,3]dioxocins and dithiocin type compounds were obtained in good to excellent yields. In the case of c ondensation of 2,7-dihydroxynaphthalene with malonaldehyde tetramethyl acet al 8,16-methano-16H-dinaphtho[2,1-d: 1',2'-g][1,3]dioxocin-2,14-diol was ob tained in high yield. (C) 1999 Elsevier Science Ltd. All rights reserved.