Abstract
The reaction of 7-isopropyl-4-methyl-1-azulenemethanol (1) with ethanol in ether yielded readily the novel compound, 1-ethoxymethyl-7-isopropyl-4-methylazulene (2), at low temperature in an ice bath, catalyzed by 20 % H2SO4. The following by-products were also obtained : 1) ether compounds : 1-ethoxymethyl-7-isopropyl-3- (7-isopropyl-4-methyl-1-azulenylmethyl) -4-methylazulene (2 B1); 1-ethoxymethyl-7-isopropyl-3- [7-isopropyl-3- (7-isopropyl-4-methyl-1-azulenylmethyl) -4-methyl-1-azulenylmethyl] -4-methylazulene (2 B1); 2) hydrocarbons : bis (7-isopropyl-4-methyl-1-azulenyl) methane (1 A1); 7-isopropyl-1, 3-bis (7-isopropyl-4-methyl-1-azulenylmethyl) -4-methylazulene (1 A2); and guaiazulene tetramers (1 A3) (1 A31 and 1 A32). All these compounds were isolated and purified by silica-gel column chromatography and confirmed by their spectroscopic (UV-vis, IR, 1H-NMR and MS) data.
