Reaction of sodium bis(2-alkoxyethoxy)aluminium hydrides

摘要: Abstract Reduction (80°) and reductive methylation (160–175°) of some geminal diphenyl-substituted olefins conjugated dienes by sodium bis(2-methoxyethoxy)aluminium hydride are described. 1,1-Diphenylethylene was reduced to give 1,1-diphenylethane as a sole product, while gave 2,2-diphenylpropane in high yield. Similarly, 1,2,2-triphenylpropane obtained from 1,1,2-triphenylethylene. Reductive cyclohexylidene diphenylmethane took place with partial rearrangement the exocyclic double bond 1-(1-cyclohexenyl)-1,1-diphenylethane main which accompanied cyclohexyldiphenylmethane 1-cyclohexyl-1,1-diphenylethane. 1,1,4,4-Tetraphenyl-1,3-butadiene at 175° underwent new type C—C cleavage leading 88/12 mixture 2,2-diphenylbutane, both formed fragments. The reduction 6,6-diphenylfulvene afforded isomers, NMR mass spectra, were identified 1-(diphenylmethyl)-1,3-cyclopentadiene (47%), 2-(diphenylmethyl)-1,3-cyclopentadiene (47%) 5-(diphenylmethyl)-1,3-cyclopentadiene (6%). this or alone 1-(1,3-cyclopentadien-1-yl)-1,1-diphenylethane, 1-(1,3-cyclopentadien-2-yl)-1,1-diphenylethane 1-(1,3-cyclopentadien-5-yl)-1,1-diphenylethane similar ratio. When 9-hydroxy-9-methylfluorene used biphenylene ethylene, hydrogenolytic 9,9-dimethylfluorene In all cases reaction is regioselective, takes exclusively phenyl-activated benzylic carbon atom acidic hydrocarbons.