Diacids XXIII and XXIV, triacid XXVII and tetraacid XVI were prepared from 3,4-secodiacid V and from nitrile XVII by modifying the isopropenyl groups in position 5 and 19. Procedures for selective esterification of the acids and the hydrolysis of their esters in position 3, 23 and 28 were elaborated and the methyl esters VII, XI, XII, XXVI, XXVIII, XXX and XXXI prepared. The structures of the derivatives prepared were confirmed by mass spectra. The antibacterial activity of the series of 3,4-secoacids derived from lupane and 19β,28-epoxy-18α-oleanane was also determined.
XXIII和XXIV两种二酸,三酸XXVII和四酸XVI是由3,4-二酸V和腈XVII经过对5位和19位异丙烯基的改造而制备的。详细阐述了酸的选择性酯化和其酯在3号、23号和28号位置的水解方法,并制备了甲酯VII、XI、XII、XXVI、XXVIII、XXX和XXXI。通过质谱确认了所制备衍生物的结构。还确定了从卢班烷和19β,28-环氧-18α-齐墩烷衍生的一系列3,4-二酸的抗菌活性。