(R)-(+)-3-Hydr-oxy-2-methoxy-carbonyl-8-methyl-8-azoniabicyclo-[3.2.1]octane l-bitartrate.

(RS)-(±)-2-Methoxy-carbonyl-3-tropinone is an important inter-mediate for the preparation of cocaine and its derivatives. The molecule in the title compound, C(10)H(16)NO(3) (+)·C(4)H(5)O(6) (-), is present as the enol tautomer. The six-membered ring adopts a half boat conformation, and the five-membered ring a slightly distorted envelope conformation.