Total synthesis of (+/-)-stemodinone via an efficient ring-exchange strategy.
A total synthesis of (+/-)-stemodinone, a tetracyclic stemodane diterpene, from the known tricyclic methyl olefin 11 is described. The key steps involve an efficient ring-exchange reaction and palladium(0)-catalyzed lactone migration. The ring-exchange strategy for controlling the stereochemistry was based on an initial Diels-Alder reaction to form a new ring followed by cleavage of the original ring. Cleavage of the original ring of the Diels-Alder adduct 9 was achieved by an initial regio- and chemoselective Baeyer-Villiger oxidation followed by the Pd(0)-catalyzed lactone-migration reaction reported by us.
Tanaka
T
T
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. t-tanaka@phs.osaka-u.ac.jp
Murakami
K
K
Kanda
A
A
Patra
D
D
Yamamoto
S
S
Satoh
N
N
Kim
S W
SW
Rahman
S M
SM
Ohno
H
H
Iwata
C
C
D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry; D016590:Aphidicolin / Q000737:chemistry; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism
D000998:Antiviral Agents; D004224:Diterpenes; D016590:Aphidicolin; C074341:stemodin; C450163:stemodinone