A very convenient, one-potsynthesis (in ca. 80% yield) of 3-Bromo-1,5- and -1,7-azulenequinones which can be used as synthones has been developed by polybromination of azulenes. Zink dust reduction and reductive acetylation of these azulenequinones were studied, and possible pathways for the present synthesis are briefly discussed.
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,
AbstractA 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.