The plant triterpenes betulin and betulinic acid (BA) are triterpenes featuring interesting pharmacologicalproperties. Starting from substituted betulinic aldehydes, we used them as lead structures for the synthesis of several γ-butyrolactones and butenolides. Their antitumor activity was examined for 15 cancer cell lines using a SRB-assay and their apoptotic action was documented by trypan-blue test