Ferrocenecarbaldehyde was reduced to methylferrocene upon interaction with
zinc tetrahydroborate in THF. The reactions proceeded rapidly (5-10 min) in
high yields (ca. 90%). Analogous results were obtained when a mechanically
activated mixture of zinc chloride and sodium tetrahydroborate or the comp
lex of zinc tetrahydroborate with dibenzo-18-crown-6, 2Zn(BH4)(2). DB-18-C-
6, was used in the reaction.