Reactions of some carbanions generated with lithium aluminium hydride

Abstract

Treatment of erythro-2,3-bis(p-methoxyphenyl)butyronitrile with lithium aluminium hydride in tetrahydrofuran gave the stable 2-anion, protonation of which gave a 2.3 : 1 erythro : threo mixture of the nitrile; in air, 1,2-bis(p-methoxyphenyl)propan-1-ol was formed by oxygenation of the anion. The same anion was produced rapidly and quantitatively from 2,3-bis(p-methoxyphenyl)crotononitrile with LiAlH₄ in tetrahydrofuran. Some reactions of carbanions generated similarly from α,α? -dicyanostilbene, 9-benzylidenefluorene, fluoren-9-ylidenemalononitrile and 1,l-diphenylethylene are described. 2,3-Bis(pmethoxyphenyl)butadiene was reduced with LiAlH₄ in tetrahydrofuran to give a mixture of (Z)- and (E)-2,3-bis(p-methoxyphenyl)but-2-ene and 2,3-bis(p-methoxypheny1)but-l-ene, probably via organoaluminium intermediates.