Ketones sugar derived

The asymmetric Baylis-Hillman reaction of sugar-derived aldehydes as chiral electrophiles with an activated olefin in dioxane water (1 1) proceeded with 36-86% de and in good yields of the corresponding glycosides (Eq. 10.47).104 The use of chiral /V-mcthylprolinol as a chiral base catalyst for the Baylis-Hillman reaction of aromatic aldehydes with ethyl acrylate or methyl vinyl ketone gave the adducts in good yields with moderate-to-good enantioselectivities in l,4-dioxane water (1 1, vol/vol) under ambient conditions.105... 

The conversion of nitroalkanes to ketoximes can be achieved by the reduction with Zn in acetic acid,112 or Fe in acetic acid.113 Nitroalkenes are direcdy reduced into saturated ketoximes by these reagents, which are precursors for ketones (see Section 6.1.4 Nef reaction). Reduction of 3-O-ace-ty lated sugar 1 -nitro-1 -alkenes with Zn in acetic acid gives the corresponding 2,3-unsaturated sugar oximes in high yield, which is a versatile route to 2,3-unsaturated sugar derivatives (Eq. 6.58).114... 

SCHEME 7. Sugar-derived ketones as catalysts for asymmetric alkene epoxidation... 

Sugar-derived ketones, catalyzed dioxirane epoxidation, 1147 Sulfanilamide, TEARS assay, 667 Sulfate ion radical, peroxydisulfate organic salts, 1014 Sulfides... 

The lower members of the homologous series of 1. Alcohols 2. Aldehydes 3. Ketones 4. Acids 5. Esters 6. Phenols 7. Anhydrides 8. Amines 9. Nitriles 10. Polyhydroxy phenols 1. Polybasic acids and hydro-oxy acids. 2. Glycols, poly-hydric alcohols, polyhydroxy aldehydes and ketones (sugars) 3. Some amides, ammo acids, di-and polyamino compounds, amino alcohols 4. Sulphonic acids 5. Sulphinic acids 6. Salts 1. Acids 2. Phenols 3. Imides 4. Some primary and secondary nitro compounds oximes 5. Mercaptans and thiophenols 6. Sulphonic acids, sulphinic acids, sulphuric acids, and sul-phonamides 7. Some diketones and (3-keto esters 1. Primary amines 2. Secondary aliphatic and aryl-alkyl amines 3. Aliphatic and some aryl-alkyl tertiary amines 4. Hydrazines 1. Unsaturated hydrocarbons 2. Some poly-alkylated aromatic hydrocarbons 3. Alcohols 4. Aldehydes 5. Ketones 6. Esters 7. Anhydrides 8. Ethers and acetals 9. Lactones 10. Acyl halides 1. Saturated aliphatic hydrocarbons Cyclic paraffin hydrocarbons 3. Aromatic hydrocarbons 4. Halogen derivatives of 1, 2 and 3 5. Diaryl ethers 1. Nitro compounds (tertiary) 2. Amides and derivatives of aldehydes and ketones 3. Nitriles 4. Negatively substituted amines 5. Nitroso, azo, hy-drazo, and other intermediate reduction products of nitro com-pounds 6. Sulphones, sul-phonamides of secondary amines, sulphides, sulphates and other Sulphur compounds... 

D. Horton and E. K. Just, Stereospecific chain-branching by C-alkylation at the ketonic and enolic positions of l,6-anhydro-2,3-0-isopropylidene-beta-D-lyxo-hexopyranos-4-ulose, Carbohydr. Res. IS 81 (1971). D. C. Baker, D. K. Brown, D. Horton, and R. G. Nickol, Synthesis of branched-chain sugar derivatives related to algarose, Carbohydr. Res. 32 299 (1974). 

Unless otherwise noted, acetone was the solvent. b Yield of deoxyiodo-sugar derivative. 0 Yield of sodium sulfonate. Yield by determination of sodium iodide consumed. Free iodine liberated. / Acetonylacetone. Corrected for solubility of sodium sulfonate in acetone. A Acetic anhydride. Isobutyl methyl ketone. 

Used for the precolumn preparation of fluorescent derivatives of aldehydes and ketones reagent suggested to be especially useful because of its application on the microlevel, for the analysis and identification of carbonyl compounds in smog, polluted air, and biochemical and pharmaceutical mixtures reagent does not appear to be useful for analysis of sugars derivatives are fluorescent in the UV as solids and in solution References 21, 22... 

Carbohydrate (Section 25.1) Naturally occurring compounds, often with the general formula C (H20) that are polyhydroxy aldehydes or ketones and derivatives formed from these includes sugars and starches. 

The intramolecular aldol reaction in the presence of a titanium Lewis acid is a viable means of preparation of cyclic compounds. The cyclization is most conveniently performed between an enol silyl ether and an acetal, because the former is a reactive enol derivative and is readily prepared by silylation of the corresponding ketone in the presence of the acetal moiety in the same molecule. Equation (12) exemplifies a substrate undergoing intramolecular ring closure mediated by TiCU [74]. The conversion of sugar derivatives to carbocycles (called the Perrier reaction [75,76]) has been reported to occur in the presence of a Lewis acid. This process involves the aldol reaction between the enol ether and acetal moieties in the same molecule promoted by a titanium salt, as illustrated in Eq. (13) [77]. The similar reaction of a different type of substrate was also reported [78]. 

SCHEME 6.67 The Wittig reaction is generally useful as applied to sugar-derived ketones. 

The naked sugars of the first generation (319, 320, 321, (+)-322, (—)-322) are useful chirons for preparing all kinds of rare sugars derivatives [180] and analogs such as C-linked disaccharides [181]. They have been converted into conduritols, cyclitols and carbahexose derivatives [174,182]. The bicyclic ketones can also be converted into their enoxysilanes and then cleaved by ozonolysis. Depending on the workup conditions, 2,5-anhydrohexaldaric acid or 2,5-anhydrohexonic acid derivatives can be readily prepared in both enantiomerically pure forms [183]. 

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