Diastereoselective synthesis of antiquorin and related polyoxygenated atisene-type diterpenes

Euphorbia Diterpenes: Isolation, Structure, Biological Activity, and Synthesis (2008–2012)

“…125 In the course of the preparation an intramolecular Diels-Alder reaction, intramolecular diazoketone cyclopropanation of an unsaturated ketone and a endocyclic regioselective cleavage of a cyclopropyl carbinyl radical were applied. 18-Hydroxy-16-atisene-3,14-dione, isolated…”

“…125 In 1989, the total synthesis of (±)-jolkinolides A, B and E from 10-(methoxycarbonyl)- The enantioselective total synthesis of the jatrophane (−)-15-O-acetyl-3-Opropionylcharaciol was carried out by Schnabel et al 137 Starting from a cyclopentane, a β-alkyl Suzuki−Miyaura cross-coupling and carbonyl addition were carried out to construct a fully functionalized triene, and a ring-closing metathesis was then applied to produce the 12-membered ring (Figures 2a, 2b and 2c). Ingenol has also been of great interest not only because of its unusual structure containing an "inside-outside" bridged BC ring, but also because of a broad spectrum of pharmacological activities.…”

Die Invasion der Stechmücken

“…Despite the intriguing biosynthetic and structural properties of these Spiraea atisine‐type alkaloids and related diterpenes, there are no reports on their total syntheses. To date, successful total syntheses towards atisane diterpenes and atisine diterpenoid alkaloids have been limited to some relatively uncomplicated compounds, such as methyl atisenoate,7a–d antiquorin,7e atisine or isoatisine ( 4 ),7d,f–k and azitine 7l. In continuation of our long‐standing interest in the chemistry of diterpenoid alkaloids,8 we wish to describe herein the first total syntheses of several atisane‐ and atisine‐type compounds with more highly oxidized skeletons including spiramilactone B ( 6 ), spiraminol ( 5 ), spiramines C and D ( 1 , 2 ), and dihydroajaconine ( 3 ), using a unified synthetic strategy that is distinctly different from previous approaches.…”

Recent Advances of Total Syntheses of Diterpenoids Starting from Carvone

“…Compounds 23 and 25 have cytotoxic activity and compound 27 exhibits anti-AIDS virus activity. The total synthesis was completed by a similar route to the trachylobane synthesis [10] (Scheme 3).…”

“…Scheme 3: Total syntheses of ent-atis-16-ene-3,14-dione (23), ent-antiquorin (25) and ent-3-hydroxy-atis-16-ene-2,14-dione (27) by Abad et al [10] Approximately 60 cladiellins, 15 briarellins, and 30 asbestinins have been discovered in corals. Rare, highly oxygenated macrocyclic rings involving a 2-oxabicyclo[4.3.0]nonane skeleton and intriguing bioactivity such as cytotoxicity and anti-malarial stimulated the interest of organic chemists and many synthetic efforts have been reported so far [11].…”