Methyl isobutyryl ketone

Treatment of the diethylketal of methyl isobutyryl ketone with morpholine did not give the above condensation product (63), but led to a mixture of di- and tetrasubstituted isomers (124 and 125). 

An, Angeloyl BAn, 3-bromoangeloyl DMB, 2,3-dihydroxy-2-methylbutyryl eDMB, (+)-e,o,JliTO-2,3-dihydroxy-2-methylbutyryl HMB, 2-hydroxy-2-methylbutyryl iB, isobutyryl K, ketone MB (-)-2-methylbutyryl Py, pyridine tDMB, (+ )-riireo-2,3-dihydroxy-2-methylbutyryl TDMB, 2-hydroxy-2-methyl-3-p-toluenesulfonylbutyryl Ts, p-toluenesulfonyl. b Attached carbon epimerized. c Cf, Chloroform. 

The process starts from a Knovengol condensation of ethyl isobutyryl acetate with 4-fluorobenzaldehyde. The reaction of S -methyl isothiourea sulfate with a,P-unsaturated ketone followed by oxidation with DDQ gives 2-(methylthio)pyrimidine. This intermediate was further oxidized by w-CPBA to yield 2-(methylsulfonyl)pyrimidine. Aromatic substitution with methyl amine and sulfonylation afford methanesulfonamide derivative. The required alcohol can be synthesized by DIBAL reduction of the corresponding ester as... 

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