Tetracyclic triterpenes
AssigneeNovartis AG
InventorsPeter Hiestand, Reto Naef, Hans-Ulrich Naegeli, Lukas Oberer, Laszlo Revesz, Hans-Jorg Roth
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Abstract
The present invention relates to 17 .alpha.-dammara compounds having immunosuppressant and antiinflammatory activity and which are useful as pharmaceuticals, particularly for use as immunosuppressant and antiinflammatory agents. Specific 17 .alpha.-dammara compounds are included per se, for example the compound of formula IC, i.e. 17 .alpha.-23-(E)-dammara-20, 23-dien-3.beta., 25-diol, which may be obtained from the flour of the shoots of the Palmyrah palm, Borassus flabellifer L. In addition, processes for the synthesis of this and other dammara compounds and intermediates thereof are described.
Claims15
A 17 .alpha.-carbonyl-dammara compound containing the ring system of formula ##STR22## wherein a is >CH--OR.sub.1, in which R.sub.1 is hydrogen or a physiologically cleavable and acceptable acyl residue, or C.dbd.O and R is a C.sub.1-8 aliphatic group, said ring system optionally containing unsaturation and optionally further substituted.
A 17 .alpha.-carbonyl-dammara compound of formula IA ##STR25## wherein a is >CH--OR.sub.1, in which R.sub.1 is hydrogen or a physiologically cleavable and acceptable acyl residue, or >C.dbd.O and R is a group attached to the carbon atom at the 17-position by a carbon atom.
A 17 .alpha.-carbonyl-dammara compound of formula IA ##STR26## wherein a is >CH--OR.sub.1, in which R.sub.1 is hydrogen or a physiologically cleavable and acceptable acyl residue, or >C.dbd.O and R is a C.sub.1-8 aliphatic group optionally comprising one or two double bonds and optionally substituted with at least one hydroxy group.
A compound of formula XIIIa ##STR28## wherein a" is >CH--OH or >C.dbd.O in free or protected form and Z is an alkali metal atom or a trialkyl tin group.
A process for the production of a 17 .alpha.-dammara compound which process comprises a) epimerising a 17 .beta.-carbonyl-dammara compound to obtain a 17 .alpha.-carbonyl-dammara compound and, optionally b) further derivatizing said 17 .alpha.-carbonyl-dammara compound.
A process for the production of 17 .alpha.-C.sub.1-8 aliphatic-dammara compound which comprises coupling a 17-carbonyl-dammara compound, in protected form as required, with an electrophile and, if desired, removing protecting groups and functionalities.
Dependencies are inferred from the claim text.