Novel syntheses of 1,6-methano[10]annulene and 4-methylazulene
Abstract
Reaction of 11, 11-dichlorotricyclo [4.4.1.01,6]-undeca-3, 8-diene (4) with potassium t-butoxide in dimethyl sulphoxide affords 1,6-methano[10]annulene (9) and 4-methylazulene (10); similar treatment of the dibromopropellane (5) yields the azulene (10), the mono-bromopropellane (11), but diminished yields of the annulene (9).