REARRANGEMENT OF AZIDOQUINONES . REACTION OF THYMOQUINONE AND 2,5-DIMETYYL1-1,4-BENZOQUINONE WITH SODIUM AZIDE IN TRICHLORACETIC ACID

The rearrangements of thymoquinone (1) and 2,5-dimethyl-l,4-benzoquinone (18) to the -γ-alkylidene-Δαβ- butenolides (2) and (19), respectively, upon reaction with sodium azide in trichloroacetic acid has been studied. In the case of thymoquinone a mechanism for this rearrangement is presented based upon the synthesis of the proposed intermediates3, 4, and 6 and their subsequent conversion into 2 under the reaction conditions. By analogy, the rearrangement of 18 is also explained. Two new rearrangements of azidoquinones to ring-contracted compounds are also described: an acid-catalyzed rearrangement to γ-lactones and a thermal rearrangement to 5-cyanocy clopentene-1,4-diones. © 1968, American Chemical Society. All rights reserved.