H. Yamamoto, T. Oritani, K. Yamashita
Aug 1, 1990
Citations
0
Influential Citations
4
Citations
Journal
Agricultural and biological chemistry
Abstract
Both chiral 4′-hydroxy and 1′,4′-dihydroxy-γ-ionylideneacetic acids (3, 4 and 5), biosynthetic intermediates of abscisic acid produced by Cercospora cruenta, were synthesized from a chiral starting material, (R)- or (S)-4-hydroxy-2,2-dimethyl-1-cyclohexanone (7). [2.3]-Sigmatropic rearrangement of (S)-1-chloromethyl-3,3-dimethyl-5-tetrahydropyranyl(THP)oxy-1-cyclohexene (8), followed by the Reformatsky reaction with 4-bromo-3-methyl-2-butenoate (10) gave (l′R,4′S)-4. The diastereomeric isomer, (l′R,4′R)-3, was synthesized in the same manner. The reaction of (S)-2,2-dimethyl-5-methylene-4-THPoxy-1-cyclohexanone (14) with a Grignard reagent prepared from (Z)-3-methyl-2-penten-4-ynyl THP ether (15) and subsequent conversion of the side chain gave (l′S,4′S)-5. These synthetic compounds confirmed the stereochemistry of natural 3, 4 and 5.