Carbinolamine lactone

The Fischer cyclization of phenylhydrazones of structure (18) gives rise to the carbinolamine-lactones (19). Reaction with methylamine, followed by reduction, then affords a short synthesis of esermethole (20a) and eserethole (20b) (Scheme... 

In a previous paper (6) we reported on the ozonation of 2-carboxy-4-nitro-N,N-dimethylaniline (I) and p-nitro-N,N-dimethylaniline (IVc). N-oxides were not found in these cases, and the products formed indicated only side-chain oxidation. The intermediacy of a carbinolamine II is indicated by the formation of the lactone III. 

A second alkaloid without the oxazolidine ring, but with the carbino-lamine system is cycloneosamandaridine (XXVII). The IR-spectrum evidences a five-membered lactone ring (band at 1780 cm i) as well as the carbinolamine group (bands at 1050/1180 cm i). The IR-spectrum of the X-acetyl compound no longer shows these hands at 1050-1180 cm i, hut an additional carbonyl frequency at 1735 cm i for an aldehyde group. The mass spectrum confirms the molecular formula as well as structure XXVII(id). 

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