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Reductive, of ketones

Reduction of ketones either with sodium and absolute alcohol, example ... [Pg.247]

Reduction of ketones, with zinc powder and alcoholic sodium hydroxide leads to secondary alcohols, for example ... [Pg.811]

Comprehensive Organic Synthesis 1991, vol 8, 307. - reduction of ketones to saturated hydrocarbons... [Pg.54]

Low-valent nitrogen and phosphorus compounds are used to remove hetero atoms from organic compounds. Important examples are the Wolff-Kishner type reduction of ketones to hydrocarbons (R.L. Augustine, 1968 D. Todd, 1948 R.O. Hutchins, 1973B) and Barton s olefin synthesis (p. 35) both using hydrazine derivatives. [Pg.97]

Carbonyl deductions. The classical Wolff-Kishner reduction of ketones (qv) and aldehydes (qv) involves the intermediate formation of a hydrazone, which is then decomposed at high temperatures under basic conditions to give the methylene group, although sometimes alcohols may form (40). [Pg.277]

A noteworthy development is the use of KH for complexing alkylboranes and alkoxyboranes to form various boron hydrides used as reducing agents in the pharmaceutical industry. Potassium tri-j -butylborohydride [54575-50-7] KB(CH(CH2)C2H )2H, and potassium trisiamylborohydride [67966-25-0] KB(CH(CH2)CH(CH2)2)3H, are usefiil for the stereoselective reduction of ketones (66) and for the conjugate reduction and alkylation of a,P-unsaturated ketones (67). [Pg.519]

Alcohol dehydrogenase-catalyzed reduction of ketones is a convenient method for the production of chiral alcohols. HLAD, the most thoroughly studied enzyme, has a broad substrate specificity and accommodates a variety of substrates (Table 11). It efficiendy reduces all simple four- to nine-membered cycHc ketones and also symmetrical and racemic cis- and trans-decalindiones (167). Asymmetric reduction of aUphatic acycHc ketones (C-4—C-10) (103,104) can be efficiendy achieved by alcohol dehydrogenase isolated from Thermoanaerohium hrockii (TBADH) (168). The enzyme is remarkably stable at temperatures up to 85°C and exhibits high tolerance toward organic solvents. Alcohol dehydrogenases from horse Hver and T. hrockii... [Pg.347]

Stereoselective reduction of ketones to alcohols by means of boiohydncle reagents (U S-BU3BH or t-BuCIBR (or lormation ol chiral alcohols)... [Pg.50]

LiBH4 reductions are usually done in tetrahydrofuran. They are also done in ethanol at —10°, ether, pyridine and diglyme. In dry pyridine the reduction of ketones goes very slowly and sometimes c)ttly takes place on aqueous work-up. " The best solvents for LitOC(CH3)3]3AlH are diglyme and tetrahydrofuran, " Reductions of unhindered ketones take... [Pg.65]

The reduction is general for a variety of substituted benzophenones Such substituents as CH3 OH, OCH3, F, Br. N(CH3)2, NO2. COOH, COOCH3, NHCOC Hreaction conditions and do not alter the course of the reduction Diarylmethanols are reduced to diarylmethanes under the same conditions and probably are the intermediates in the reduction of ketones [26] Triethylsilane also can be used as a reducing agent in trifluoroacetic acid medium [27J This reagent is used for the reduction of benzoic acid and some other carboxylic acids under mild condiUons (equation 14) Some acids (phthalic, sue cinic, and 4-nitrobenzoic) are not reduced under these conditions [27]... [Pg.946]

Recent advances in the asymmetric catalytic reduction of ketones using chiral oxazaborolidines as ligands 98MI64. [Pg.273]

Another important synthetic method for the reduction of ketones and aldehydes to the corresponding methylene compounds is the Woljf-Kishner reduction. This reaction is carried out under basic conditions, and therefore can be applied for the reduction of acid-sensitive substrates it can thus be regarded as a complementary method. The experimental procedure for the Clemmensen reduction is simpler however for starting materials of high molecular weight the Wolff-Kishner reduction is more successful. [Pg.63]

The reduction of ketones to secondary alcohols and of aldehydes to primary alcohols using aluminum alkoxides is called the Meerw>ein-Ponndorf-Verley reduction. The reverse reaction also is of synthetic value, and is called the Oppenauer oxidation. ... [Pg.199]

The lithium aluminum hydride-aluminum chloride reduction of ketones is closely related mechanistically to the Meerwein-Ponndorf-Verley reduction in that the initially formed alkoxide complex is allowed to equilibrate between isomers in the... [Pg.20]

So far only two groups have reported details of the use of ionic liquids with wholecell systems (Entries 3 and 4) [31, 32]. In both cases, [BMIM][PF(3] was used in a two-phase system as substrate reservoir and/or for in situ removal of the product formed, thereby increasing the catalyst productivity. Scheme 8.3-1 shows the reduction of ketones with bakers yeast in the [BMIM][PF(3]/water system. [Pg.339]

Scheme 5. Corey s diastereoselective catalytic reduction of ketone 21. Scheme 5. Corey s diastereoselective catalytic reduction of ketone 21.
With this single example we have in tact described two uses of enzymes in alicyclic chemistry, the reduction of ketone groups and the resolution of racemic mixtures. [Pg.327]

Figure 8.2 Reduction of ketone with alcohol dehydrogenase from Thermoanaerobacter brockii using glucose-6-sulfate as a hydrogen source [3],... Figure 8.2 Reduction of ketone with alcohol dehydrogenase from Thermoanaerobacter brockii using glucose-6-sulfate as a hydrogen source [3],...

See other pages where Reductive, of ketones is mentioned: [Pg.111]    [Pg.510]    [Pg.42]    [Pg.43]    [Pg.54]    [Pg.169]    [Pg.310]    [Pg.247]    [Pg.37]    [Pg.61]    [Pg.63]    [Pg.64]    [Pg.81]    [Pg.351]    [Pg.141]    [Pg.27]    [Pg.394]    [Pg.89]    [Pg.193]    [Pg.194]   
See also in sourсe #XX -- [ Pg.1182 ]




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Alcohols by reduction of ketones

Alcohols reduction of ketones

Alcohols, preparation by reduction of ketones

Amination, by reduction of a ketone

Amination, by reduction of a ketone with hydroxylamine

And reduction of ketones

Asymmetric Borane Reduction of Ketones

Asymmetric Organosilane Reduction of Ketones

Asymmetric Organosilane Reduction of a,-Unsaturated Ketones

Asymmetric Reduction of Ketones Using Bakers Yeast

Asymmetric Reduction of Ketones Using Nonmetallic Catalysts

Asymmetric Reduction of Ketones Using Organometallic Catalysts

Asymmetric Reduction of Prochiral Ketones Catalyzed by Oxazaborolidines

Asymmetric reduction of a prochiral ketone (chloroacetophenone)

Asymmetric reduction of acetylenic ketone

Asymmetric reduction of aldehydes and ketones

Asymmetric reduction of ketones

Asymmetric reductive acetylation of ketones

Baker s yeast Reduction of ketones

Biocatalytic Reductions of Ketones to Alcohols

Boranes reduction of ketones

Borohydride reduction of ketone

CBS reduction of ketones

Chemoselective reduction of keton

Diastereoselective reduction of ketones

Dynamic kinetic resolution of racemic ketones through asymmetric reduction

Enantioselective Borane Reduction of Ketone

Enantioselective reduction of ketones

Enantioselectivity catalytic reduction of ketone

Enantioselectivity reduction of prochiral ketones

Enzymatic Reduction of Ketones

From reduction of aldehydes and ketones

Gribble reduction of diaryl ketones

Hydride reduction of aldehydes and ketones

Hydrogen transfer reduction of ketones

Lithium isopropoxide reduction of steroidal ketones

Organosilane Reduction of Ketones

Organosilane Reduction of a, p-Unsaturated Ketones

Organosilane Reductive Amination of Aldehydes and Ketones

Oxazaborolidines as Asymmetric Inducers for the Reduction of Ketones and Ketimines

Protection of ketones against reduction

REDUCTION OF KETONES BY USE

REDUCTION REACTIONS OF ALDEHYDES AND KETONES

Reaction II.—Reduction under certain Conditions of Aromatic Ketones

Reaction XII.—Reduction of Aldehydes and Ketones to Pinacones

Reduction of Aldehyde and Ketone Carbonyls

Reduction of Aldehydes and Ketones Using Whole Cells

Reduction of Aldehydes and Ketones to Alcohols

Reduction of Aldehydes and Ketones to Hydrocarbons

Reduction of Aldehydes and Ketones with Poly(Methylhydrosiloxane)

Reduction of Aldehydes in Preference to Ketones

Reduction of Aldehydes, Ketones, and Carboxylic Acid Derivatives

Reduction of Aliphatic Ketones

Reduction of Aromatic Ketones

Reduction of Aryl Ketones

Reduction of Cyclic Ketones

Reduction of Enones in Preference to Ketones

Reduction of Hydroxy and Amino Ketones

Reduction of Ketones Using Enantioselective Borohydride Reagents

Reduction of Ketones and Imines

Reduction of P-hydroxy ketones

Reduction of a,-Unsaturated Ketones in Hexamethylphosphoric Triamide

Reduction of a,/3-unsaturated ketones

Reduction of a,p-acetylenic ketones

Reduction of a- ketones

Reduction of a-amino ketones

Reduction of a-halo ketones

Reduction of a-heterosubstituted keton

Reduction of a-hydroxy ketones

Reduction of a-substituted ketones

Reduction of aldehydes and ketones

Reduction of aldehydes or ketones

Reduction of cyclopropyl ketone

Reduction of ketones

Reduction of ketones using whole cells

Reduction of ketones with borane

Reduction of prochiral ketones

Reduction of saturated ketone

Reduction of steroidal ketones

Reduction of unsaturated aldehydes and ketones

Reduction of unsaturated ketone

Reduction of unsymmetrical ketones

Reduction, of ketones, with

Reductions of a, 3-unsaturated aldehydes and ketone

Reductive acetylation of ketones

Reductive acylation, of ketones

Reductive alkylation of aldehydes and ketones

Reductive amination of ketones

Reductive cyclization of ketones

Reductive of ketones and aldehydes

Sodium Borohydride Reduction of an Aldehyde or Ketone

Stereoselectivity reduction of ketones

The Phytochemical Reduction of Ketones

The Reduction of a,-Unsaturated Ketones

The Reduction of a-Substituted Ketones

The reduction of aldehydes and ketones

The reduction of aldehydes, ketones and esters

Wolff-Kishner reduction, of aldehydes and ketones

Yeast reductions of ketones

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