Diastereoselective total synthesis of both enantiomers of epolactaene.
A stereocontrolled total synthesis of both the (+)- and (-)-epolactaene ((+)- and (-)-1) enantiomers from tetrahydropyran-2-ol is described. The following reactions in this synthesis are particularly noteworthy: (1) the stereoselective construction of the conjugated (E,E,E)-triene by a combination of kinetic deprotonation and thermodynamic equilibration, (2) the E-selective Knoevenagel condensation of beta-ketonitrile 33 with a chiral 2-alkoxyaldehyde, (3) a diastereoselective epoxidation achieved using a bulky nucleophile (TrOOLi) and an appropriate protecting group, (4) the mild hydrolysis of an alpha-epoxy nitrile by silica gel on TLC facilitated by hydroxyl-mediated, intramolecular assistance.
Hayashi
Yujiro
Y
Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan. hayashi@ci.kagu.tus.ac.jp
Kanayama
Jun
J
Yamaguchi
Junichiro
J
Shoji
Mitsuru
M
D002855:Chromatography, Thin Layer; D020650:Combinatorial Chemistry Techniques; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D007700:Kinetics; D015394:Molecular Structure; D010407:Penicillium / Q000737:chemistry; D011090:Polyenes / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013816:Thermodynamics
D004852:Epoxy Compounds; D007202:Indicators and Reagents; D011090:Polyenes; C095351:epolactaene