Enantioselective synthesis of the C-14 to C-5 cyclopentane segment of jatrophane diterpenes

Progress in the Preparation of Jatrophane Diterpenes

“…[46] Two years later, this methodology was applied to the total synthesis of (-)-15-acetyl-3-propionyl-17-norcharaciol (97). [47] The retrosynthetic analysis is shown in Scheme 14.…”

Isolation and Structure Elucidation of Diterpenes from Euphorbia pannonica, E. esula and E. falcata

“…EUP-26 (9) was found to be identical in all of its characteristics, including the 1 H and 13 C NMR spectral data, with the jatrophane diterpene isolated earlier from Euphorbia peplus.…”

“…The 1 H and 13 C NMR spectroscopic investigations proved that EUP-13 (10, salicinolide) was a 17-ethyl bis-homojatrophane-type lactone, salicinolide, and EUP-17 (11, euphosalicine) was the modified jatrophane euphosalicin. Both compounds were described previously from Euphorbia salicifolia.…”

“…Further interesting diterpene esters with great structural variety and noteworthy biological activities have been isolated from Euphorbiaceae species. [13][14][15][16][17][18][19][20][21] In 1995, the workgroup of Department of Pharmacognosy, University of Szeged initiated a research programme with the aim of investigating the secondary metabolites of Hungarian Euphorbia species. In the course of these studies, many diterpene esters of different skeletal types have been isolated.…”

“…The results presented in Table 3 In the case of the diterpenes isolated from E. falcata (12)(13)(14)(15)(16)(17)(18), weak or moderate cell growthinhibitory activities were detected; substantial effects were recorded only at the higher tested concentration (30 µg/mL) for compound 14, which showed significant activity in all 3 cell lines a nicotinoyl group on C-9 instead of a keto group (such as in 5) suggested that a 9-nicotinoyl group is also essential for high MDR-reversing activity. Among the premyrsinanes, EFAL-3 (12), which was inactive based on the FAR data and had low synergistic activity, differs structurally from the others because of the absence of the 7-OBz and 15-OAc groups, which therefore seem to be important for the activity of the compounds.…”