摘要:
Treatment of acetals derived from ortho substituted benzaldehyde chromium tricarbonyl complexes and methanol with homoallylic alcohol and titanium tetrachloride produces the corresponding (RS,RS,SR,RS)-cis-2-aryl-4-chloro-tetrahydropyran complexes completely diastereoselectively. Thus, by this method, homochiral (R)-(-)-omicron-anisaldehyde chromium tricarbonyl is converted, after decomplexation, to homochiral (R,S)-(+)-cis-2-omicron-anisyl-4-chlorotetrahydropyran.