Homogeneous hydrogenations ofα, β-unsaturated compounds using pentacyanocobaltate (II) anion as catalyst system

Abstract

Hydrogenation of some a, fl-unsaturated carbonyl compounds using potassium pentacyanocobaltate (II), KaCo(CN)~, asa homogeneous catalyst has been investigated. Thus, hydrogenation of l-carvone (I), mesityl oxide (4), 2-cyclohexenone (8) and benzalacetone (6) afforded the corresponding dihydrocompounds. Hydrogenation of ~-ionone (10) afforded a mixture of the a, //-dihydroccmpounds (14) and (15). In all these tases, it was observed that the reaction proceeded to completion only in the presence of added base. Hydrogenation of 5a-androstl-en-17 ~-ol-3-one acetate (19) afforded the saturated compound, 5a-androst-17 q 3-one (20) in 60~ yield. It was found that other steroid enones and dienones were not reduced by this eatalyst system.

Chemistry and Biology of the Caged Garcinia Xanthones

“…Similar rearrangements at the C ring may account for the structure of gaudispirolactone ( 23 ). [31, 32] Gambogoic acid ( 24 ), [18, 33] dihydroisomorellin ( 25 ), [20b] and isomoreollin ( 26 ) [34] are a few representative examples of caged xanthones with a modified C9=C10 double bond.…”