4-[[5-(Hydroxymethyl)-8-methyl-3,4-dihydro-2H-pyrido[4,3-e]-1,3-oxazin]-3-yl]crotonic acid C??? ??, ??, ??

4-[[5-(Hydroxymethyl)-8-methyl-3,4-dihydro-2H-pyrido[4,3-e]-1,3-oxazin]-3-yl]crotonic acid ?? ?? ? ???

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4-[[5-(Hydroxymethyl)-8-methyl-3,4-dihydro-2H-pyrido[4,3-e]-1,3-oxazin]-3-yl]crotonic acid ?? ??