Homologization ketones, cyclic

Diazomethane reacts with ketonic compounds according to the reactions to give epoxides and homologated ketones. If the ketone employed is cyclic, only a single... 

Addition of the diazoalkane nucleophile is followed by an reaction with ring-closure or a homologous ketone is formed with a 1,2-alkyl rearrangement (shift). Spirooxiranes are produced from cyclic ketone derivatives with diazomethane (Eq. 86). ... 

Homologation of cyclic ketones.1 The reagent reacts with cyclohexanone (1) to give l-(isocyanomethyl)-1 -cyclohexanol (2) in 77 % yield. This is converted by methanolic... 

In extensive investigations Muller and his co-workers181 showed that appreciably better yields are obtained in this homologation of cyclic ketones on catalysis by boron trifluoride etherate. For example, cyclooctanone affords 44% of the nine-membered ring ketone in this way, compared with 15-20% in the uncatalysed reaction.181... 

Via intermediates Homologization of cyclic ketones via cyclic a-hydroxydiazo compds. s. 26, 661... 

Aldehydes can be converted into ketones, ketones homologated, and cyclic ketones ring expanded via the insertion of an RCH unit [derived from the dibromoalkyl-lithium (43)] into the substrate the reaction may lead to mixtures of products depending on the nature of R and R (Scheme 36). ... 

Functional Groups other than Acetylenes Allenes, and Olefins homologation of cyclic ketones (Scheme 75). 

This procedure illustrates a new three-step reaction sequence for the one-carbon ring expansion of cyclic ketones to the homologous tt,/3-unsaturated ketones. The key step in the sequence is the iron(III) chloride-induced cleavage of the central bond of trimethyl-silyloxycyclopropanes which me obtained by cyclopropanation of trimethylsilyl enol ethers. The procedure for the preparation of 1-trimethylsilyloxycyclohexene from cyclohexanone described in Part A is that of House, Czuba, Gall, and Olmstead. ... 

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... 

In contrast to a,(3-unsaturated phosphonium salts, ot,(3-unsaturated phosphonates (161)1331 alkylate ali-cyclic ketone enolates efficiently, while the homologous diethyl butadiene phosphonate (162)133bintramolecular cyclization. Heathcock reports that... 

Homologation of ketones (1, 369-370 6, 252-253 8, 222). Ethyl diazoacetate is recommended as the most useful diazoalkane for monohomologation of cyclic and acyclic ketones without formation of epoxides as by-products. One advantage is that the usually slow reaction can be catalyzed by BF3 etherate (or triethyloxonium tetrafluoro-borate). 

Cyclic ketones react to form the higher homologs for example, cyclohexanone is converted to cycloheptanone (63%). ... 

Which homologous diazoalkanes, a mixture of cycloheptanones and spirooxiranes results. In cyclic ketones equatorial attack is usually favored. ... 

Application of the above series of homologation reactions to cyclic ketones provides a route to ring-expanded products. Due to the constraints of ring systems, the preference for die migration of one bond over the other during these reactions is influenced by an additional set of factors, among which include... 

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