๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Enantioselective total syntheses of (+)-decursin and related natural compounds using catalytic asymmetric epoxidation of an enone

โœ Scribed by Tetsuhiro Nemoto; Takashi Ohshima; Masakatsu Shibasaki

Publisher
Elsevier Science
Year
2003
Tongue
French
Weight
326 KB
Volume
59
Category
Article
ISSN
0040-4020

No coin nor oath required. For personal study only.

โœฆ Synopsis

The enantioselective total syntheses of (รพ)-decursin (1) and related natural dihydropyranocoumarins (2)-prantschimgin (3), (รพ)decursinol (4), and (รพ)-marmesin (5) were achieved for the first time using catalytic asymmetric epoxidation of an enone as the key step. Catalytic asymmetric epoxidation of the enone was effectively promoted by the novel multifunctional asymmetric catalyst generated from La(O-i-Pr) 3 , BINOL, and Ph 3 AsvO in a 1:1:1 ratio to afford epoxide in 94% yield and 96% ee, which was recrystallized to give optically pure epoxide. After conversion to the common key intermediate (2)-peucedanol ( 7), all natural dihydropyranocoumarins were synthesized through palladium-catalyzed intramolecular C-O coupling reactions. A possible reaction mechanism of the catalytic asymmetric epoxidation of enones is also described based on X-ray analysis, laser desorption/ionization time-of-flight mass spectrometry, kinetic studies, and asymmetric amplification studies.

๐Ÿ“œ SIMILAR VOLUMES

Enantioselective total syntheses of nove
Enantioselective total syntheses of novel PKC activator (+)-decursin and its derivatives using catalytic asymmetric epoxidation of an enone
โœ Tetsuhiro Nemoto; Takashi Ohshima; Masakatsu Shibasaki ๐Ÿ“‚ Article ๐Ÿ“… 2000 ๐Ÿ› Elsevier Science ๐ŸŒ French โš– 99 KB

The catalytic asymmetric total syntheses of (+)-decursin and three related natural products, (+)-decursinol, (-)-prantschimgin and (+)-marmesin, were achieved for the first time using catalytic asymmetric epoxidation of an enone as the key step. The catalytic asymmetric epoxidation of enone was foun