Raney nickel deuteration catalyst

Methyl P-D-galactopyranoside, treated with deuterated water in the presence of Raney nickel as catalyst and ultrasonic radiation, gives rapid C-deuteration at... 

The aforementioned deuterated derivatives were prepared by way of reduction of a ketone, aldehyde, or ester with sodium borodeu-teride, or by deuteroboration of an alkene. An interesting reaction, perhaps eventually applicable to direct deuteration of polysaccharides, was reported by Koch and Stuart413 and by them and their coworkers,41b who found that treatment of methyl a-D-glucopyranoside with Raney nickel catalyst in deuterium oxide results in exchange of protons attached to C-2, C-3, C-4, and C-6. In other compounds, some protons of CHOH groups are not replaced, but the spectra may nevertheless be interpreted with the aid of a- and /3-deuterium effects. 

The usual conditions of catalytic hydrogenation can be applied, with certain modifications, for the saturation of carbon-carbon double and triple bonds. Platinum and Raney nickel are the usual catalysts described. It is important that catalysts used for deuteration shall be pretreated with deuterium noble-... 

D2]-9-Octadecene A solution of 9-octadecyne (5 g) in purified dioxan (125 ml) is deuterated in the presence of pretreated Raney nickel. The very selective reaction ceases after absorption of one equivalent of deuterium. The catalyst is then filtered off, the solution is evaporated, and the crude residue is dissolved in sufficient ether to give an approximately 10% solution. After cooling to ca. —45° for 2 h, the resulting crystals are removed further cooling to ca. —50° gives a second fraction. On distillation of the two fractions at 2-3 mm the product of m.p. 140-142° is obtained. 

Dioxane, used as the washing agent for catalyst preparation and also as a reaction media, was spectrograde quality (Matheson, Coleman Bell), In initial experiments no precautions were taken to exclude water from dioxane but this led to water contamination. In later experiments dioxane was stored over a molecular sieve, Linde Type 3A (Matheson, Coleman Bell). Deuterium gas was obtained from Liquid Carbonic Corporation and had an isotope purity of 99.7%. The 99.8% heavy water (DgO), used for preparations of deuterated Raney nickel and as a washing agent, was from Isotopes and Stotler Isotopes Company. 

The duplicate experiments in Table 2 (E7, E8, ElO or E13A, E14A) show that approximately 45 to 50 mL of D2 per gram of catalyst are available from the deuterated Raney nickel under the conditions of the investigation. The amount... 

Modification of deuterated Raney nickel with L-glutamic acid also results in lower deuterium contents in the products but does not drastically alter deuterium distributions (experiments D28B and D28C). In contrast to other work on C=C double bonds [12], little asymmetric induction was obtained. For example, the deuteriumation of III over MRNiD(A) and IV over MRNiD(B) produced products with optical purities of 0.4 and 1.1% respectively. Low enantioselectivi-ties from these catalysts might result from processes associated with extensive exchange. 

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