Diastereoselective [2+2] photocycloaddition of chiral cyclic enones with olefins in aqueous media using surfactants.
We conducted diastereodifferentiating [2+2] photocycloadditions of  cyclo-hexenones modified with a chiral 8-(p-methoxy phenyl)menthyl auxiliary with olefins in water. Although the photoreaction didn't proceed at all in pure water owing to very low solubility, the use of surfactants [sodium dodecyl sulfate (SDS) or dodecylamine hydrochloride (DAH)] and additive (organic solvent) enabled the reactions to progress with moderate to high conversions and yields. Furthermore, we synthesized a new menthol derivative substrate containing a (p-octyloxy)phenyl group for enhancing hydrophobicity, and elucidated that this new substrate was found to be a suitable chiral auxiliary in this asymmetric photoreaction in aqueous system. The additive effect of organic molecules on the yield and diastereoselectivity of the photo-adducts is also discussed.
Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan. y-west@ms.naist.jp
Yasuhiro
Y
Nishiyama
Mikiko
M
Shibata
Takuya
T
Ishii
Tsumoru
T
Morimoto
Hiroki
H
Tanimoto
Ken
K
Tsutsumi
Kiyomi
K
Kakiuchi
D000475:Alkenes / Q000737:chemistry*; D061565:Cycloaddition Reaction / Q000379:methods*; D003517:Cyclopentanes / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry; D006844:Hydrocarbons, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D008027:Light; D010782:Photolysis; D013237:Stereoisomerism; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D000475:Alkenes; D003517:Cyclopentanes; D005030:Ethylenes; D006844:Hydrocarbons, Cyclic; D013501:Surface-Active Agents; D014867:Water; C036216:ethylene