REGIO-CONTROLLED PRENYLATION AND GERANYLATION OF 3-FURYLMETHYLMAGNESIUM BROMIDE. SELECTIVE SYNTHESES OF 3-SUBSTITUTED FURANOID AND 2-SUBSTITUTED 3-METHYLFURANOID TERPENES.

Article abstract of DOI:10.1246/bcsj.56.1446

Coupling reactions of 3-furylmethylmagnesium bromide with prenyl and geranyl diethyl phosphates gave 2-substituted 3-methylfurans, rosefuran and sesquirosefuran, as the main products. When the reactions were carried out in the presence of a catalytic amount of copper(I) iodide, normal coupling occurred and 3-substituted furans, perillene and dendrolasin, were formed in good yields. The related naturally occurring 3-substituted thiophene, 3-(4-methyl-3-pentenyl)thiophene, was also synthesized from 3-thienylmethylmagnesium bromide and prenyl diethy phosphate.