Methyl 3-eleostearate hydrogenation

Hilditch and Pathak (58) studying the catalytic reduction of methyl eleostearate, found that the reaction at 110° and at 170° was extremely selective in the presence of Raney nickel. No methyl stearate was formed until 90% of the linoleate had been transformed into octadeceno-ates. Ehrhart (59) used Raney nickel to hydrogenate compounds of the type RCH(CN)NHCOR The nitrile was reduced to the amine, but the amide was untouched. 

A hydroboration-protonolysis procedure for the conversion of conjugated enynes to dienes is far superior to partial hydrogenation over Lindlar s catalyst, in terms of stereoselectivity and yields280. Ratovelomanana and Linstrumelle reported the synthesis of methyl a-eleostearate (equation 163) and methyl punicate by employing this strategy280. 

Hydrogenation of methyl p-eleostearate (methyl frani,fran5,fra s-9,ll,13-octadecatrienoate) with [Cr(CO)3(arene)] yields the diene products from 1,4-addition trans-9-cis- 2- and CK-10-fran5-13-oc-tadecadienoates). With a-eleostearate (methyl d5,fran5,fra i-9,ll,13-octadecatrienoate), stereoselective 1,4-reduction of the trans,trans-diene moiety yields linoleate (cis,cis-9,l2) accompanied by cm,Irani-1,4-dienes which are formed from the isomerization of a- to p-eleostearate. ... 

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