Asymmetric synthesis by the intramolecular haloetherification reaction of ene acetal: discrimination of prochiral dienes in cyclohexane systems.
A novel asymmetric synthesis of the cyclohexane derivative functionalized by some substituents has been developed from the diene acetals (1), prepared from the corresponding diene aldehyde and (+)-hydrobenzoin. The treatment of 1 with NBS in the presence of MeOCH2CH2OH predominantly afforded 2 in a stereoselective manner. Subsequent alkylation of the methoxyethoxy group produced the optically active cyclohexene compounds (3) in good yields. The stereoselective chemical modification of the remaining olefin in 3 was made by OsO4-oxidation.
Fujioka
Hiromichi
H
Graduate School of Pharmaceutical Sciences, Osaka University 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan. fujioka@phs.osaka-u.ac.jp
Kotoku
Naoyuki
N
Sawama
Yoshinari
Y
Kitagawa
Hidetoshi
H
Ohba
Yusuke
Y
Wang
Tsung-Lung
TL
Nagatomi
Yasushi
Y
Kita
Yasuyuki
Y
D000080:Acetals / Q000737:chemistry*; D003510:Cyclohexanes / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
D000080:Acetals; D003510:Cyclohexanes; D004987:Ethers