Synthetic route to the chiral intermediate to methyl (2-pentyl-2-cyclopentenyl)acetate (11) was established using the asymmetric allylic substitution reaction of 13 as the key step. The allylic substitution reaction of 13 proceeded smoothly in the presence of Pd(η{sup}3-C{sub}3H{sub}5)Cl{sub}2 and Trost's ligand as a chiral ligand in 92 yield with 54 enantiomeric excess. Demethoxycarbonylation of 14 in DMS0 at 180℃ gave the important intermediate 11 in excellent yield (96). Consequently, the important intermediate 11 for the preparation of (+)-cis-methyl dihydrojasmonate, which has the strong jasmine odor, was prepared from commercially available 2-pentyl-2-cyclopenten-lone (6) in 84 yield with 77 selectivity in 4 steps. Furthermore, asymmetric allylic substitution reaction was carried out using Pd(η{sup}3-C{sub}3H{sub}5)Cl{sub}2 and (S)-BINAP in environmentally benign media. Firstly, reaction was carried out in water in the presence of cetyltrimethylammonium hydrogen sulfate as the surfactant gave the alkylated product 14 in 89 yield. Secondly, ionic liquid such as 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) which is insoluble in water and alkanes but solubilizes many transition metal catalysts was used as the reaction media. The reaction in bmimBF{sub}4 gave 14 in 90 yield.
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