Ketalazation of the triacetylbenzene (1) with 2,2-dibromomethyl-1,3-propanediol by using 4-methyl-benzenesulfonic acid as catalyst, yielded 1,3,5-tri-(1-methyl-2,6-dioxaspiro-4,4-dibromomethyl- cyclohexyl)benzene (2), which reacted with 5,5-dimethyl-4,6-dioxa-1,3-cyclohexanedione in C₂H₅ONa giving 1,3,5-tri-[7-(7-methyl-2,2-di-ethoxycarbonyl-6,8-dioxaspiro[3.5]-nonyl)]benzene (3). Treatment of 3 with 2,2-dihydroxymethyl-1,3-propanediol in CHCl₃ afforded 1,3,5-tri-[7-(7-methyl-2,2-di- (2,2-dihydroxyl- methyl-3-hydroxy-propoxycarbonyl)-6,8-dioxaspiro[3.5]-nonyl)]benzene (4) in 47.7% yield. The compound 4 and its intermediates were identified by IR, 1H NMR, MS spectra and elemental analysis.

Key words: 1,3,5-triacetyl benzene, 2,2-dibromomethyl-1,3-propanediol, dendrimer, 5,5-dimethyl-4,6-di-oxa-1,3-cyclohexanedione