Collect. Czech. Chem. Commun.
1980, 45, 1964-1973
https://doi.org/10.1135/cccc19801964
3,4-Seco-3,28-lupanedioic acids substituted in the side chain at C(5)
Irena Valterová, Jiří Klinot and Alois Vystrčil
Department of Organic Chemistry, Charles University, 128 40 Prague 2
Abstract
A series of derivatives of 3,4-secolupane-3,28-dioic acid (II-XIV, XIX-XXI) containing an oxygen-containing functional group in the side chain at C(5) was prepared from nitrile I and ketone XVII. In the case of derivatives III-XIV both series of C(4)-epimers, a and b, were obtained. The configuration at C(4) was derived on the basis of the formation of an intramolecular hydrogen bond in compounds IX and XIII from the chiroptical properties of benzoates VII and it was confirmed by a stereospecific synthesis of the 4S-derivative XIIIa from 24-nor-ketone XV.
