- Acetylene method (by machine translation)
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In the presence of a catalyst alkoxide or an amino N,N - salt, the saturated or unsaturated ketone or aldehyde compound is subjected to acetylene hydrogenation to obtain the corresponding alkynol compound, and has the advantages of moderate reaction rate, mild reaction, easy control, easy separation of the product, recyclable solvent and the like. (by machine translation)
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Paragraph 0057-0059
(2019/11/29)
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- ETHYNYLATION PROCESS
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A process for the manufacture of an acetylenically unsaturated alcohol comprising reacting formaldehyde, an aldehyde or a ketone (a carbonyl compound) with acetylene in the presence of ammonia and an alkali metal hydroxide, the molar ratio of the alkali metal hydroxide to the carbonyl compound being less than 1 : 200. The reaction products, which depending on the starting carbonyl compound are propargyl alcohol or 1-monosubstituted or 1,1-disubstituted derivatives thereof, are of use as intermediates in the synthesis of many useful end products, inter alia in the field of vitamins and carotenoids.
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- Preparation of higher alpha, beta-unsaturated alcohols
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Higher α,β-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetatesor diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.
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- SEMIHYDROGENATION OF ACETYLENES; MODIFIED LINDLAR CATALYST
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The effect of doping Lindlar catalyst with different metal salts (shown in Table 1) on selectivity, during semihydrogenation of some acetylenes to the corresponding olefins, has been studied.Lindlar catalyst modified with MnCl2 has been found to be more selective and reproducible.
- Rajaram, J.,Narula, A. P. S.,Chawla, H. P. S.,Dev, Sukh
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p. 2315 - 2322
(2007/10/02)
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- Catalytic rearrangement
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Process for converting secondary and tertiary acetylenic carbinols to the corresponding alpha,beta-unsaturated carbonyl compounds by rearranging the carbinol with (trilower alkyl-, tricycloalkyl-, triaryl- or triarylalkyl-siloxy)-vanadium oxide catalyst in the presence of a silanol where either the vanadium oxide or the silanol contains a phenyl group substituted with at least one electron withdrawing group.
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