SYNTHESIS OF PIPERIDINE DERIVATIVES. PART II

Diethyl 1-ethyl-2: 6-diphenl.4-oxy-4-ethyl (and 4-phenyl)-piperidine.3 : 5-dicarboxylates have been synthesised by the action of the appropriate Grignard reagent on diethyl r-ethyl-2:6 diphenl^-4^-PiPeri­doue-3: 5-dicarboxylate. The high and the low melting varieties of the latter, mentioned by Petrenko­Kritschenko have now been shown to be keto and enol forms.