[2+2] Cycloaddition reaction of cycloheptatriene with dichlorodetene. A novel and efficient synthetic strategy for the synthesis of 2-hydroxyazulene

摘要

The reaction of cycloheptatriene with dichlorodetene, generated by the treatment of trichloroacetyl chloride with activated zinc in dry diethyl ether, affords 9,9-dichlorobicyclo[5.2.0]nona-2,4-dien-8-one 2 as a major product together with 3',3'.9.9-tetrachlorsospiro(bicyclo[5.2.0]noa-2,4-diene-8.2'-oxetan)-4'-one 3.