Thiele acetoxylation

Finally, Thiele acetoxylation of quinones, by treatment with acetic anhydride and sulfuric acid, is another excellent method of introducing functionality at an alkene carbon atom, for further synthetic elaboration (equation 50)196. This reaction was recently used as a key synthetic step in the total synthesis of metachromin-A, a useful sesquiterpene quinone moiety197. 

An especially interesting case of oxygen addition to quinonoid systems involves acidic treatment with acetic anhydride, which produces both addition and esterification (eq. 3). This Thiele-Winter acetoxylation has been used extensively for synthesis, stmcture proof, isolation, and purification (54). The kinetics and mechanism of acetoxylation have been described (55). Although the acetyhum ion is an electrophile, extensive studies of electronic effects show a definite relationship to nucleophilic addition chemistry (56). 

Thiazoles, synthesis of, 6, 8 Thiele-Winter acetoxylation of quinones, 19, 3... 

Thiele-Winter Reaction (Acetoxylation) (Thiele Reaction)... 

Kende s elegant racemic synthesis is still one of the shortest total synthesis of dendrobine (82), although no less than eight syntheses and four additional synthesis attempts followed (151). As Yamada in his first attempt, Kende et al. started with cheap, commercially available thymol, which was converted via thymoquinone and Thiele-Winter-acetoxylation into the known l,2,4-triacetoxy-3-isopropyl-6-methylbenzene (168) (Scheme 17) (178). 

The Thiele-Winter Acetoxylation of Quinones J. F. W. McOmie and J. M. Blatchly... 

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