V. Kovalev, E. Shokova, Alexander Shmailov
Jul 1, 2010
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0
Influential Citations
9
Citations
Journal
European Journal of Organic Chemistry
Abstract
The self-acylation of 1-adamantylacetic acid (1) in trifluoroacetic anhydride, catalyzed by triflic acid, proceeds through the formation of the mixed 2,4-bis(1-adamantyl)acetoacetic-trifluoroacetic anhydride 2, and it was used as an efficient approach to previously unknown 2,4-bis(1-adamantyl)aceto-acetic acid (3), its esters 4-6 and amides 7-11, and the sterically hindered 1-adamantyl(1-adamantylacetyl)ketene (12). The latter is stable in solution and can be isolated as a neat solid. Addition of methanol or primary amines to 12 gave the corresponding derivatives of acid 3. Acid 3 was decarboxylated to 1,3-bis(1-adamantyl)acetone (22), whereas the heterocyclization of phenyl ester 6 with thiourea gave two isomeric adamantylated thiouracils 23 and 24. The structures of N-benzylamide 7 and thiouracil 23 were confirmed by single-crystal X-ray analysis. The utilization of the self-acylation method for the conversion of some other aliphatic acids is discussed and preliminarily tested.