are obtained by reaction of AlH3 with pyrrolidine enamines of acyclic and cyclic ketones. Enamines of α-substituted cyclohexanones are converted to 3-alkylcyclohexenes. Those derived from disubstituted acetaldehydes are only poorly hydrogenolysed as is the dienamine derived from Δ1,9-octalone. 1-N-Pyrrolidinocyclo-octene is unique in giving cyclo-octane in the hydrogenolysis reaction; trans-cyclo-octene
significant directive effect of the 2-axial hydroxy group appeared in the LiAlH4, NaBH4, and Zn(BH4)2 reduction of cyclohexanone, while the 3-axial hydroxy group exhibited a steric hindrance. The distance between the carbonyl carbon and the hydroxy group which interacts with the hydride reagent is mainly responsible for such a difference. In the reduction of Na[B(OAc)3H], both the 2- and 3-axial hydroxycyclohexanones
Borohydride reduction of Δ1,9 2-octalone: Cation influence and amine addition effects
作者:E. D'Incan、A. Loupy、A. Maïa
DOI:10.1016/0040-4039(81)89014-4
日期:1981.1
Proton removal of Δ1,92-octalone ocaurs uhen reacted with NBu4BH4 in aprotic solvents while 1-2 reduction is important uith NaBH4 in THF. Both are inhibited uhen NaBH4 reduction is performed in the presence of amines, leading thus to highly selective formation of saturated alcohols.