Reactivity of Carbon Nucleophiles with Disubstituted Tricarbonyl(pentadienyl)iron(1+) Cations: Application to the Synthesis of Lasiol and Epi-Lasiol
The reactions of 1,2-dimethyl-, 1-phenyl-2-methyl-, 1,4-dimethyl-, and 1-phenyl-4-methyl- substituted tricarbonyl(pentadienyl)iron(1+) cations (3a, 3b, 4a, 4b respectively) with lithium dimethylcuprate and with sodium dimethylmalonate were examined. Regiospecific nucleophilic attack was observed in cases where the directing effects of the two substituents were matched. The reaction of 4a with sodium dimethyl methylmalonate was examined, and the product was subsequently transformed into a mixture of epi-lasiol and lasiol, a terpene with a novel rearranged skeleton.
The reaction of cations3a, 3b, 4a, and 4b with dimethylcuprate and with sodium dimethylmalonate were examined. A short synthesis of 14 used the cation 4a.