2006

Oxazole derivativesR 0220 Preparation of 2-(1-Chloroalkyl)-4,5-dimethyloxazoles and (E)-2-Alkenyl-4,5-di-

methyloxazoles. — Cyclocondensation of 2,3-butandione monoxime with aromatic aldehydes and subsequent treatment of the thermally instable N-oxides (III) with POCl3 or SOCl2 results in chlorination of the 4-methyl group. When aliphatic aldehydes are used, chlorination at the 2-methylene is observed rather than at the 4-methyl position. — (ZHANG, H.; YAN, P.-F.; ZHANG*, G.-L.; Synthesis 2006, 11, 1763-1766; Chengdu Inst. Biol., Chin. Acad. Sci., Chengdu 610041, Peop. Rep. China; Eng.) — Mais

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