PROCESS FOR THE PREPARATION OF 2,3-DIHYDROPYRANE DERIVATIVES

摘要

Title comds. [I; R1 = alkyl group, benzyl group or (alkyl group, halogen, alkoxy group, or nitrogen group substitued) benzyl group; R2 = piperidine group were prepd. by reaction of enamine compds (II) with methylvinylketone. Thus, 134.2g -phenylpropionaldehyde was reacted with 111g piperidine and 130g potassium carbonate at room temp. for 30 min and the product mixed with 75g met- hlvinylketone followed by mixing for 30 min to give 3-benzyl-6-methyl-2-(1-piperidine)-3,4-dihy- dro-2H-pyrane