Synthesis and Reactivities of 1,5- and 1,7-Azulenequinone Derivatives. A Highly Convenient,One-Pot Synthesis of 3-Bromo-1,5- and −1,7-Azulenequinones by Bromination of Azulene,

A very convenient, one-pot synthesis (over 80% yield) of 3-bromo-1,5- and ?1,7-azulenequinones has been developed by bromination of azulene in aqueous tetrahydrofuran. Reduction of 3-bromo-1,5- and ?1,7-azulenequinones with tin or zinc powder in acetic acid gave the parent 1,5- and 1,7-azulenequinones, and further reduction products.