Enantiospecific synthesis of the cubitane skeleton.
The fully substituted 12-membered macrocycle of the cubitane-type diterpenoids has been assembled in an enantioselective manner following a novel "bridge-and-cut" strategy. Hydroxyalkylation of (S)-carvone afforded a carvonylgeraniol, which underwent transannular cyclization on treatment with samarium diiodide in THF. Fragmentation of one of the shorter bridges of the resulting [8.2.2]bicycle liberated the 12-membered ring with the desired cis-arrangement of the isopropenyl side chains.
Schöttner
Elisabeth
E
TU Braunschweig, Institutes of Organic, Inorganic and Analytical Chemistry, Hagenring 30, 38106 Braunschweig, Germany.
Wiechoczek
Maren
M
Jones
Peter G
PG
Lindel
Thomas
T
D002384:Catalysis; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D004224:Diterpenes