Synthesis of 2-Azaadamantan-6-one: A Missing Isomer

Abstract

2-Azaadamantan-6-one and its Boc and ethylene ketal derivatives were synthesized from 9-oxo endo-bicyclo[3.3.1]non-6-ene-3-carboxylic acid. Similarly, the Cbz, Boc, and ethylene ketal derivatives of 2-azaadamantan-4-one were synthesized from endo-bicyclo[3.3.1]non-6-ene-3-carboxylic acid. Key steps were Curtius rearrangements to form benzyl carbamates, followed by spontaneous intramolecular attack of the carbamate nitrogen on transient bromonium ion or epoxide intermediates to effect ring closure to azaadamantane intermediates. The reaction sequence leading to 2-azaadamantan-6-one is consistent with the formation of a transient tetracyclic keto aziridine intermediate.

Structure–Activity Relationship of Antischistosomal Ozonide Carboxylic Acids

“…Step 1 . To a solution of 2-Boc-2-azaadamantan-6-one ( 59 ) (4.00 g, 15.91 mmol) in dry EtOH (100 mL) was added pyridine (2.08 g, 26.25 mmol) followed by methoxyamine hydrochloride (1.99 g, 23.87 mmol). The resulting mixture was stirred at rt for 12 h and then concentrated in vacuo.…”

“…The synthesis of 53 began with the conversion of the mono-ketal of adamantane-2,6-dione (49) 32 to its oxime ether 50 in high yield. This was followed by coozonolysis 30 The synthesis of ozonide 24 began with the formation of oxime ether 60 from the Boc-protected azaadamantanone 59, 33 which then underwent coozonolysis 30 with keto ester 51 to form ozonide ester 61 in 36% yield (Scheme 11). Ester hydrolysis of 61 furnished ozonide phenol 62 in 98% yield, which was then alkylated with ethyl bromoacetate to form ozonide ester 63 in quantitative yield.…”

A water-soluble aza-adamantyl nitroxide radical and its complexes with β-cyclodextrin derivatives

“…N-Trifluoroacetyl-protected 2-aza-adamantane, Z-1, was synthesized in four steps from 2-adamantanone (1) according to the reported procedures. [42][43][44][45] Under microwave conditions, RuO 4 -catalyzed hydroxylation of Z-1, using a NaIO 4 -RuCl 3 system, gave Z-2. Finally, hydrolysis of Z-2, followed by oxidation with sodium tungstate and urea hydrogen peroxide, afforded the target radical Z-3.…”

Facile construction of the all-bridge-position-functionalized 2,4,6,8-tetraazaadamantane skeleton and conversion of its N-functionalities

“…Considerable progress has also been made in the post-synthesis of azaadamantanes. For example, azaadamantanes with multiple substituents including 4-substituted, 3 a ,13 2,4-, 14 2,6-, 4 3,5- 15 disubstituted, and polysubstituted 3 b ,9 c , d ,11 c ,16 1-azaadamantanes, as well as 2-, 17 4- 18 substituted, 2,6-disubstituted, 19 and polysubstituted 9 b ,17 a ,20 2-azaadamantanes have been simply synthesized. Diazaadamantanes such as 2,6-disubstituted 21 and polysubstituted 20 b ,22 2,6-diazaadamantanes, as well as 4-substituted 23 and polysubstituted 6 b , c ,7 b ,23,24 1,3-diazaadamantanes have also been masterly prepared.…”