A divergent and stereoselective approach for the syntheses of (-)-zeylenol, (+)-6-O-benzoylzeylenol, (+)-uvarigranol E and (+)-uvarigranol F

A common, divergent, efficient, and stereoselective approach to the total syntheses of four carbasugars, namely, (-)-zeylenol, (+)-6-O-benzoylzeylenol, (+)-uvarigranol E and (+)-uvarigranol F from d-mannose derived key intermediate 14 is described. This intermediate was synthesized using mixed aldol condensation, Grignard reaction and ring closing metathesis as key steps by our previous method in nine steps from d-mannose. From this intermediate, we achieved the syntheses of (+)-6-O-benzoylzeylenol, (+)-uvarigranol F in three steps, (+)-uvarigranol E in four steps and improved synthesis of (-)-zeylenol.

Cytotoxic polyoxygenated cyclohexene derivatives from the aerial parts of Uvaria cherrevensis

Three previously undescribed polyoxygenated cyclohexene derivatives named cherrevenol M (1), cherrevenol N (2), and cherrevenone (3), together with nine related known analogues 4-12 were isolated from the ethyl acetate fraction partitioned from the methanol extract of the aerial parts of Uvaria cherrevensis (Annonaceae). The determination of the structures and their relative configurations of the isolated compounds were established by spectroscopic techniques, electronic circular dichroism (ECD) analysis as well as comparison with the literature data. For cherrevenone (3), the relative and absolute configurations were also confirmed by using X-ray diffraction and ECD techniques, respectively. Compounds isolated except for compounds 8 and 10 were evaluated for their cytotoxic activity and cherrevenone (3) showed moderate cytotoxic activity against all cancerous cell lines except for ASK cell line with ED₅₀ values ranging from 1.04 ± 0.13 to 10.09 ± 4.31 μM.