Total syntheses of the sesquiterpenoids (+)-trans-dracunculifoliol and (+)-4-hydroxyoppositan-7-one
摘要:
Sesquiterpenoids (+)-trans-dracuncuflifoliol (1) and (+)-4-hydroxyoppositan-7-one (2) were prepared stereoselectively from enantiomerically pure (7aR)-7a-methyl-1,2,5,6,7,7a-hexahydro-4H-inden-4-one ((-)-6), whose synthesis was described herein. Conjugate addition of the organocopper (1) reagent 10 to (-)-6, followed by epimerization of the ring junction, generated 3 of the 4 contiguous chiral centers of both natural products. (c) 2005 Elsevier Ltd. All rights reserved.
Total syntheses of the sesquiterpenoids (+)-trans-dracunculifoliol and (+)-4-hydroxyoppositan-7-one
摘要:
Sesquiterpenoids (+)-trans-dracuncuflifoliol (1) and (+)-4-hydroxyoppositan-7-one (2) were prepared stereoselectively from enantiomerically pure (7aR)-7a-methyl-1,2,5,6,7,7a-hexahydro-4H-inden-4-one ((-)-6), whose synthesis was described herein. Conjugate addition of the organocopper (1) reagent 10 to (-)-6, followed by epimerization of the ring junction, generated 3 of the 4 contiguous chiral centers of both natural products. (c) 2005 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Asymmetric Conjugate Addition of Trialkylaluminium Reagents to Trisubstituted Enones: Construction of Chiral Quaternary Centers
作者:Magali Vuagnoux-d'Augustin、Alexandre Alexakis
DOI:10.1002/chem.200701001
日期:2007.11.26
vinylalane species undergo enantioselective conjugateaddition to a wide range of 2- or 3-substituted enones (cyclopent-2-enones, cyclohex-2-enones, 3-methyl cyclohept-2-enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3CN)4]BF4 or [CuOTf]2C6H6) and tropos-phosphoramidite-based ligand. Thus, chiral quaternarycenters can be built, with up to 98% ee after rigorous