Paraldehyde → 1,4-Benzodioxin

Participants

Reaction Steps

Reaction of 3,5-(1,1-dimethylethyl)-2-hydroxybenzenemethanol (7.03 g, 0.03 mol), paraldehyde (13.2, 0.3 mol), p-dioxane (150 mL) and p-toluenesulfonic acid hydrate (0.57 g, 0.003 mol) as described in Example 4, provided after distillation 4.12 g (52% yield, GLC purity 99%), of 6,8-(1,1-dimethylethyl)-2-methyl-4H-1,3-benzodioxin. Crystallization from methanol provided 3.0 g of pure benzodioxin, mp 59°-61° C.; 1H-NMR (CDCl3)δ1.20 (9H, s), 1.30 (9H, s), 1.50 (3H, d, J=5 Hz), 4.83 (2H, dd, J=5 and 14 Hz), 5.10 (1H, q, J=6 Hz), 6.72 (1H, d, J=2 Hz), 7.10 (1H, d, J=2 Hz); IR (CDCl3)λmax 2955, 1490, 1455, 1410 cm-1 ; MS m/e 262, 218, 203, 177, 161; UVλmax (ethanol) 224 nm (ε=4650), 280 nm (ε=1190).

Provenance & Evidence