Approach to the synthesis of antitumor quassinoids from labdane diterpenes: an efficient synthesis of a picrasane-related intermediate.
[structure: see text]. The tetracyclic ketal 24, a suitable intermediate for the synthesis of antitumor pentacyclic quassinoids, has been efficiently prepared from communic acids (5a-c), via methyl ketone 9. The synthetic sequence from 9 to 24 consists of 15 steps in 12% overall yield.
Barrero
A F
AF
Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain. afbarre@goliat.ugr.es
Alvarez-Manzaneda
E J
EJ
Alvarez-Manzaneda
R
R
Chahboun
R
R
Meneses
R
R
Cuerva
J M
JM
Aparicio
M
M
Romera
J L
JL
D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis*; D004224:Diterpenes / Q000138:chemical synthesis*; D010946:Plants, Medicinal / Q000737:chemistry; D036702:Quassins; D013729:Terpenes
D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes; D036702:Quassins; D013729:Terpenes; C426926:picrasane