Asymmetric synthesis of 2-aryl-tetrahydropyrans via arene chromium tricarbonyl methodology 2: 2-Aryl-3-ethyl-4-chloro-tetrahydropyrans
Davies SG., Donohoe TJ., Lister MA.
Treatment of acetals derived from o-tolualdehyde chromium tricarbonyl and o-anisaldehyde chromium tricarbonyl with Z- and E-hex-3-en-1-ol and titanium tetrachloride generated, after decomplexation, completely stereoselectively the corresponding r-2-o-aryl-c-3-ethyl-c-4-chloro-tetrahydropyrans and r-2-o-aryl-c-3-ethyl-c-4-chloro-tetrahydropyrans respectively. This methodology was applied to the asymmetric synthesis of homochiral (R,R,S)- and (S,R,R)-2-o-anisyl-3-ethyl-4-chloro-tetrahydropyran from homochiral o-anisaldehyde chromium tricarbonyl and Z- and E-hex-3-en-1-ol respectively. © 1991.