Ketones acyclic—

Ketones. Acyclic ketones are named (1) by adding the suffix -one to the name of the hydrocarbon forming the principal chain or (2) by citing the names of the radicals R and R followed... 

Rate constants and Arrhenius parameters for the reaction of Et3Si radicals with various carbonyl compounds are available. Some data are collected in Table 5.2 [49]. The ease of addition of EtsSi radicals was found to decrease in the order 1,4-benzoquinone > cyclic diaryl ketones, benzaldehyde, benzil, perfluoro propionic anhydride > benzophenone alkyl aryl ketone, alkyl aldehyde > oxalate > benzoate, trifluoroacetate, anhydride > cyclic dialkyl ketone > acyclic dialkyl ketone > formate > acetate [49,50]. This order of reactivity was rationalized in terms of bond energy differences, stabilization of the radical formed, polar effects, and steric factors. Thus, a phenyl or acyl group adjacent to the carbonyl will stabilize the radical adduct whereas a perfluoroalkyl or acyloxy group next to the carbonyl moiety will enhance the contribution given by the canonical structure with a charge separation to the transition state (Equation 5.24). 

Ketones. Acyclic ketones are named (1) by adding the suffix -one to the name of the hydrocarbon forming the principal chain or (2) by citing the names of the radicals R1 and R2 followed by the word ketone. In addition to the preceding nomenclature, acyclic monoacyl derivatives of cyclic compounds may be named (3) by prefixing the name of the acyl group to the name of the cyclic compound. For example,... 

The Corey-Bakshi-Shibata reduction (CBS reduction) is a highly enantioselective method for arylketones, diaryl ketones, and dialkylketones. In addition, cyclic a,p-unsaturated ketones, acyclic a,p-unsaturated ketones, and a,p-ynones are reduced enantioselectively in a 1,2-fashion. The high enantioselective nature of this reduction relies on the chiral oxazaborolidine catalyst, shown in the reaction scheme, in the presence of borane or a dialkylborane. Reviews (a) Singh, V. K. Synthesis 1992, 605-617. (b) Deloux, L. Srebnik M. Chem. Rev. 1993,93,163-1. (c) Corey, E. J. Helal, C. J. Angew. Chem. Int. Ed. 1998, 37. 1986-2012. 

HSCH2CH2SH, VO(OTf)2, CH3CN, rt, 72-95% yield. Aldehydes are protected selectively in the presence of ketones. Acyclic thioacetals are formed similarly. This author has also used RuCT to affect this transformation. ... 

The reaction of a,)3 Unsaturated acid chlorides with enamines has become a useful method for the a,a -annulation of ketones " . Acyclic ketones are converted into aminocyclohexenones in good yield and hydrolysis gives the corresponding cyclohexa-1,3-dione " (Scheme 143). Application of the reaction to enamines of cyclohexanones gives bicyclo[3,3,l]nonane-2,9-diones . The yields are greatly affected by the experimental conditions used and, in the presence of triethylamine, the course of the reaction is changed completely and tetrahydrochromanones are usually the main or only product " (Scheme 144). 

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