Pseudoakuammigol

The structure LVI (R = H) for pseudoakuammigol receives convincing confirmation from the fragmentation patterns observed in the mass spectra of pseudoakuammigol and its deuterated derivatives LVIa and LVIb the structure (XLVIII R = H) for pseudoakuammigine itself can therefore be regarded as firmly established. Since these mass spectra,... 

In accordance with the structure XLVIII (R = OMe), O-methylakuammine is reduced by lithium aluminum hydride to O-methyl-akuamminol (LVI R = OMe), an indoline base which contains two alcoholic hydroxyl groups, and which, like pseudoakuammigol (LVI R = H), gives rise to an (amorphous) isopropylidene derivative. 

On the basis of this structure (LXXIV) for picraline, picralinol must be the diol LXXV. The latter differs from the proposed structure for pseudoakuammigol (LVI R = H) only in that it possesses a hydrogen atom attached to Na instead of a methyl group accordingly, iVa-methylation of picralinol should yield pseudoakuammigol. This methylation has been realized by the lithium aluminum hydride reduction of the triformyl derivative (LXXVI) of picralinol, which affords pseudoakuammigol directly (51a). 

The mass spectrum of diol (237) shows peaks at m/e 252,237, and 197 characteristic of the dihydroeburnamenyl residue which also appear in the spectrum of pleiomutine (230) (see preceding Section). Peaks appearing at mje 196, 178, and 166 are characteristic for the aliphatic part of pseudoakuammigol (239). 

The peak mje 265 ab) (see preceding Section) in the mass spectrum of diol (237) shows that the linkage position in the dihydroebumamenyl part is C(14). The fragment m/e 383 (ad), which corresponds to aa of the pleiomutine (230) spectrum, and the peaks in the region m/e 648 to mje 452 (Table 2), show that an aromatic carbon of the pseudoakuammigol part is involved in the dimeric linkage. 

Fragmentation under electron impact of 2,16-dihydroakuammicine AND pseudoakuammigol... 

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