P Alkoxyketones

Alternatively, the alcohol group of the initial adducts of 119 such as 124 may be oxidized to the ketone 125 (Eq. 125). The resultant p-alkoxyketone now relieves ring... 

Lithium tetrahydridoaluminate I lithium iodide 5 11-1,3-Diol monoethers from p-alkoxyketones... 

Room temperature imidazolium ionic liquids have been shown to be useful solvents for the Michaelis-Arbuzov rearrangement, sometimes allowing the reaction to be performed at room temperature in a short period of tirne. Halolactones, which are the products of halolactonisation of y,5-unsaturated acids, have been shown to be dehalogenated by trialkyphosphites in the presence of water. This makes a useful alternative to the commonly used reduction by tributyltin hydride. The reactions of dibromoethane and dibromopropane with silyl phosphites have been studied. Mono and diphosphonoalkanes (37) and (38) were prepared and their chemical properties were studied. In the reaction of trifluoromethylated P-alkoxyketones with tris(trimethylsilyl)phosphite, a mixture of the 1,2- and 1,4-adducts (39) and (40) is produced. 

Baba et al had developed further the activation of OH by InCl3 for direct substitution by using carbon nucleophiles of compounds with active methylene, P-alkoxyketones or indole [159] (Figure 8.68). The authors had proposed two possibilities for the reaction mechanism, one a direct substitution of the activated OH by the nucleophiles, and another that is through a dimeric ether from the condensation of the alcohols. The former was expected by the authors to be more probable. 

SCHEME 8.19. The boron-mediate diastereoselective aldol reactions using p-alkoxyketones. 

OH and SH insertions are also known. They are used for the synthesis of a-alkoxyketones by reaction of a-diazocarbonyl compounds with alcohols, and for the synthesis of a-phenylthioketones, using thiophenol (see review of Maas, 1987, p. 204). 

Ramahcandran, P. V. Lin, H. Reddy, M. V. R. Brown, H. C. 2003. Synthesis of homoallylic chiral tertiary alcohols via chelation-controlled diastereoselective nucleophilic addition on a-alkoxyketones Application for the synthesis of the Cl-Cl 1 subunit of 8-epi-fostriecin. Org. Lett. 5 3755-3757. 

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