addition of nucleophiles to α-methyl-β-methylene carbonyl compounds combined with the hydromagnesiation reactions of 2-alkyl-substituted 1,3-dienes affords a practical, efficient stereo- and regio-controlledaldolsynthesis.
Rhodium(I)- or ruthenium(II)-catalyzed direct coupling of vinyl ketones with aldehydes and the subsequent reduction to give aldol derivatives anti-selectively
作者:Susumu Sato、Isamu Matsuda、Masahiro Shibata
DOI:10.1016/0022-328x(89)80096-8
日期:1989.11
A vinyl ketone reacts with an aldehyde to give an α-methylene-β-hydroxyalkanone with the concomitant formation of the vinyl ketone dimer in the presence of catalytic amount of RhH(PPh3)4 or RuH2(PPh3)4 under almost neutral conditions. The selectivity of the cross-coupling product is remarkably improved in the presence of an extra mole of aldehyde. This type of cross-coupling is explained by the intermediacy