| abstract |
Procedure for the preparation of tetracyclononane derivatives of formula **formula** where R1, R2 and R3, which may be the same or different, are hydrogen atoms or alkyl radicals with 1 to 3 carbon atoms and is a radical of formula CH2CH2 or CH2-R4 where R4 is a hydrogen atom or an alkyl radical of 1 to 6 carbon atoms, a cyclohexyl radical, a phenylalkyl radical in which the alkyl part is of 1 to 6 carbon atoms, or a radical phenyl optionally substituted by a halogen atom or by an alkyl or alkoxy radical of 1 to 6 carbon atoms, with the proviso that when A is a radical of formula CH-R4, at least one of R1, R2, R3 and R4 is other than a hydrogen atom and pharmaceutically acid addition salts thereof. |