Organic Chemistry Lab procedure question?

Question

Propose the synthetic procedure for catalytic hydrogenation of 10 g triolein using cyclohexene as a hydrogen donor.

This is a question regarding my O Chem lab. I have the basic idea of what to do, but need some supplementary help. Someone help me please!

Answer 1

The procedure you are referring to is called transfer hydrogenation. Transfer hydrogenation is the addition of hydrogen (H2; dihydrogen in inorganic and organometallic chemistry) to a molecule from a source other than gaseous H2. It is applied in industry and in organic synthesis, in part because of the inconvenience and expense of using gaseous H2. One large scale application of transfer hydrogenation is coal liquifaction using "donor solvents" such as tetralin.

The following is a typical catalytic transfer hydrogenation procedure using formic acid as the hydrogen donor. In your case, substitute triolein  for the substrate X and cyclohexene for formic acid.

A solution of X (9.80 g, 39 mmol) in absolute ethanol (60 mL) was added to 0.98 g of 10% Pd/C (50% water). To this mixture was added 96% formic acid (9.35 g, 195 mmol) dropwise over 30 min. The reaction mixture was then heated at 708C for 2 h and allowed to cool to 20 8C. The catalyst was removed by suction filtration through Celite, and the solids were washed with absolute ethanol (25 mL). The combined filtrate and wash was added to a mixture of 2-propanol/12 N HCl (120 mL/6.5 mL) dropwise. The resulting solution was treated with ethyl acetate (30 mL), and the suspension thus obtained was left at 48Covernight. The solid was filtered with suction, washed with ethyl acetate (10 mL), and dried at 50 8C under reduced pressure to give 4; yield: 8.8 g (77%); mp 150 – 151 8C;.