4- -ones methylation

Chiral enolates of 1,3-dioxalan-4-ones, methyl l,3-oxa2ohdine-4-carboxylates,and 1,3-iml-da2ohdine-4-ones derived from chiral natural sources such as fS -prohne, fS -serine, and fS -threonine are added to nltroalkenes in high diastereoselectivity fScheme 4,12, ... 

Pfister and co-workers129 recently prepared derivatives of the third possible thieno-l,2-thiazin-4-one. Methyl 2-chlorosulfonylthiophene-3-car-boxylate (161) with glycine methyl ester gave intermediate 162, which afforded 4- hydroxy- 3- methoxycarbonyl - 2 H - thieno [3,2-e] -1,2- thiazine 1,1 -dioxide (163) upon heating with base. Alkylation of 163 with methyl iodide/sodium hydride gave 164 which afforded a thieno-1,2-thiazine analog (165) of piroxicam (29) when heated with 2-aminopyridine (Scheme 6). 

Hydroxymaltol (3,5-dihydroxy-2-methyl-4H-pyran-4-one) Methyl-4(7T)-pyran-4-one (2-methyl-4/7-pyran-4-one)... 

Pfister and co-workers recently prepared derivatives of the third possible thieno-l,2-thiazin-4-one. Methyl 2-chlorosulfonylthiophene-3-car-boxylate (161) with glycine methyl ester gave intermediate 162, which afforded... 

Pyrimidin-2-ones, methylation of, 254 Pyrimidin-4-ones, methylation of, 254, 255... 

Quinoxalin-4-ones, methylation of, 255 Quinoxalin-3-one 1-oxides, 218, 238-239 Quinoxalin-3-one-2-carboxylic acid, 205, 207... 

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