Convenient synthesis of 3,5,7-trimethyl-1-azonia-adamantanes

Abstract

A convenient synthesis of 3,5,7-trimethyl-1-azonia-adamantanes (2) is described. The esterification of cis, cis-1,3,5-tris(hydroxymethyl)-1,3,5-trimethylcyclohexane (3) with trifluoromethanesulfonic anhydride, followed by the reaction with primary amines, yields azonia-adamantanes 2. On the other hand, the esterification of triol 3 with TFAA also affords cis, cis-1,3,5-tris[(trifluoroacetoxy)methyl]-1,3,5-trimethylcyclohexane (5). However, the reaction of triester 5 with 2-(2-aminoethyl)pyridine does not give the corresponding azoniaadamantane, but 2,2,2-trifluoro-N-[2-(pyridin-2-yl)ethyl]-acetamide (6). The β-methylene protons in azonia-adamantane 2a [R = 2-(pyridin-2-yl)ethyl] are very active. Both acids and bases react with 2a to yield 2-vinylpyridine. The elimination reaction of 2a with lithium methoxide is available for the synthesis of 3,5,7-trimethyl-1-aza-adamantane (1).

Hydride-Transfer Domino Rearrangement of Glycine-Containing Dioxa-azawurtzitane

“…11 The NOE differential spectra of lactone-imine 9-Na indicated a similarity to the structure of lactone 5. 8,12 The imino proton of 9-Na correlated with the two adjacent methylene protons. The ab initio energy calculation (HF/6-31G*) for 9-H 11,13 also supported the structure of 9-Na.…”