These analogous ones normally are carried through way hemissintese from the triterpeno, being the modifications carried through in hidroxila in C-3 position and the acid carboxlico in C-17 position (Figure 5). An important hemisinttico.conhecido triterpeno as RPR 10361 (Figure 5), is a made up of low mass molar not peptdico capable to interact with gp 41 (LABROSSE et al, 2000), as well as stabilizing the complex gp120-gp 41 (LABROSSE et al, 1997), thus blocking the viral infection in inferior concentrations 10 nM.Seu esteroisomero, the IC9564 (Figure 5) is also powerful inhibitors fusing, capable to act in gp120 viral (HOLZ-SMITH et al, 2001) Had to the good results of the RPR103611 and IC 9564 (Figure 5) analogous ones of this composition have been synthecized. As example, we can cite the attainment of dihidro IC 9564 (Figure 6), that it is the chemical preparation saw hemissintese from the acid betulinico (SUN et al, 2003) that, after hidrogenao of the double linking, acetilao of hidroxila in C-3 position, in ascetic presence of anhydride and formation of acyl chloride in position in C-28 position, using itself chloride of oxalila, supplies the intermediary.

The coupling under basic conditions between intermediary 9. The coupling under basic conditions between intermediate 9 and 10 (HOLZ-SMITH et al, 2001), followed of the desproteo of the groups acetila and benzila in hidrxido presence of of sodium, supplies the white molecule, dihidro of sodium, supplies the white molecule, dihidro IC9564, 50 EC =0,4 M indicating the double linking of the isopropilideno group could not be important for the biological activity. However, its protected precursory intermediary presents a EC50> 28 M, what he indicates the importance of hidroxila (C-3) and of the acid carboxlico (C-28) he exempts for the biological activity.