3-Acetoxyquinuclidine

In contrast to the enantiomers of (145), both enantiomers of 3-acetoxyquinuclidine (aceclidine, 149) are potent muscarinics, and the S-enantiomer is only approximately one order cf magnitude less potent than acetylcholine. 

H. Weinstein, S. Maayani, and S. Srebrenik, Mol. Pharmacol., 11(5), 671 (1975). A Theoretical and Experimental Study of the Semirigid Cholinergic Against 3-Acetoxyquinuclidine. 

Strong cholinomimetic properties were shown by the tertiary analogue of compound (XLVII) - the hydrochloride (or salicylate) of 3-acetoxyquinuclidine (IVa) named aceclidine [122-126]. 

Thus, of the aliphatic acid esters studied 3-acetoxyquinuclidine (aceclidine) and 3-acetoxymethylquinuclidine had the greatest cholinergic activity. Increase of the distance between the acyl group and the quinuclidine ring, increase of the... 

Acetoxyquinuclidine added to a soln. of 2-bromoacetylnaphthalene in chloroform, refluxed 3 hrs., and stirred overnight at room temp. 3-acetoxy-l-[2-oxo-2-(2-naphthyl)ethyl]quinuclidinium bromide (Y 92%) dissolved in abs. ethanol, and hydrogenated with 5%-Pd-on-carbon at room temp, and 3.5 atm. overnight l-(2-naphthyl)ethanol. (Y 82%). F. e. s. R. J. Adamski et al.. Synthesis 1973, 221. 

Interestingly, DABCO (9, pATa = 8.5), with relative rate of 1, accelerated the reaction more than 3-acetoxyquinuclidine 20 (pATa = 9.3) or 3-chloroquinucilidine 21 (pATa = 8.9). Presumably, DABCO was a more effective catalyst, because of the two basic nitrogen atoms. 

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