Hydroxy-des-N-methyl-a-obscurine, C I~H~~O ?~\ T ? , has been isolated froin L . fEabelliforme and a structure assigned to it on the basis of physical evidence. A s t r i l c t~~r e is assigned t o Lycopodium allraloid L.5, which we have named flabellidine, on the basis of physical evidence and its chemical derivation from lycodine. The mass spectra of hydroxy-des-N-methy1-aobscurine, flabellidine, and flabelline are discussed.The alltaloids of L. flabelliforme were first investigated by i\/Ianslte and Marion ( I ) , who isolated lycopodine (the major alkaloid), nicotine, and six bases, which they designated by number only. Alkaloid L.1 is now ltnown t o be dihydrolycopodine (2), L.2 t o be acetyldihydrolycopodine (3), and L.6 t o be a mixture of a-and P-obscurine (4). The structures of lycopodine and its derivatives (2) and of a-and p-obscurine (5) are now known. The structure of alkaloid L.5, t o which we have assigned the trivial name flabellidine, is discussed in this paper, leaving alkaloids L.3 and L.4 of the original six still uninvestigated.By using chromatographic and countercurrent distribution methods, an additional seven alltaloids have been isolated from L.flabell.iforme in this laboratory. Thus Young (6) has reported the isolation of two new alltaloids, flabelliformine and flabelline, t o each of which a structure has been assigned (7,8). Alam (9) has found four alkaloids of ltnown structure (clavolonine, lycodine, annotinine, and des-N-methyl-a-obscurine) and a new base hydroxy-des-N-methyl-a-obscurine, the structure of which is discussed in this paper.The structure assigned t o hydroxy-des-N-methyl-a-obscurine I rests on physical evidence as insufficient material was available t o investigate its chemistry.The presence of a hydroxyl group in I is inferred from its infrared spectrum, which, in Nujol and in chloroform, shows a pealt a t 3510 cm-l. The position of this peak in chloroform solution is not shifted upon dilution, thereby indicating that the hydroxyl group is intrainolecularly hydrogen bonded. Aside from the pealt in the hydroxyl region, the spectrum of this compound is remarkably similar t o that of a-obscurine (11) and des-Nmethyl-a-obscurine (111). The spectra of the three are reproduced in Fig. 1 for the region 3600-1500 cm-I.The ultraviolet spectrum of I (l:f:;OH 255 mp, log E = 3.78) is almost identical with that of I1 (~::i~~ 255 mp, log E = 3.75) and I11 (l:f:{OH 255 mp, log E = 3.81). From the spectral evidence i t appears that I must have the same chromophoric system as I1 and 111.The mass spectrum of the hydroxy compound shows a molecular weight of 276, corresponding t o the molecular formula C16H2402b?2. This formula differs in colnposition from I11 (C16H240N2) by one oxygen atom, suggesting t h a t the new base may be a simple hydroxy derivative of the latter. T h e fragmentation pattern of I , discussed later, is in agreement with this proposition.The nuclear magnetic resonance (n.m.r.) spectrum of I shows a three proton doublet For personal use only.
The ring expansion of xanthene derivatives to dibenz [b,f]oxepin is already known. Thus Anet and Bavin (1) have reported the synthesis of dibenz [b,f]oxepin and 10-methyldibenz [b,f]oxepin by Wagner-JlIeerwein rearrangement of 9-xanthenemethanol and 9-hydroxyinethyl-9-inethylxanthene. Store recently, Whitloclc (2) has reported the forination of dibenz [b,f]oxepin in 61yo yield \\-hen xantl~ylium perchlorate is treated with ethereal diazoinethane. We wish to report on the reaction of 9-xanthenemethylamine under the conditions of the Demjanov rearrangement (3), in I\-hich ring expansion has also been observed.9-Xantheneinethylamine (4, 5) was prepared from 9-xantheneacetic acid (6) in the follo\ving manner. The acid was converted into its acid chloride with tl~ionyl chloride and this in turn into the azide, which underwent Curtius rearrangeinent (7) to the isocyanate. Treatinent of the isocyanate \~i t h alkali, however, gave N,N1-di(9-xanthenemethy1)urea instead of the ainine. The forination of the urea was avoided by conversion of the crude isocyanate into the ethylurethane followed by hydrolysis of the urethane t o 9-xanthenemethylainine, which was isolated as the hydrochloride salt, in a yield of 41.5y0 based on 9-xantheneacetic acid. T h e yield was improved t o 52.5y0 by treatment of the crude isocyanate with benzyl alcohol followed by reduction of the benzylurethane to the ainine.9-Xanthenemethj~lainine was treated with nitrous acid in acetate buffer under experimental conditions norn~ally employed in the Deinjanov rearrangeinent. T h e crude product was worked up as described in the Experimental section and separated into an olefinic and a n alcoholic fraction by column chromatography on alumina. The alcoholic fraction, comprising 96yo of the product, was shown t o be a inixture of 9-xanthenemethanol and 10,ll-dihydrodibenz[b,f]oxepin-lO(l1,H)-01 in a ratio of 1:4. T h e ring-expanded alcohol is formed in an overall yield of 65% based on the ainine. T h e composition of the inixture was established by nuclear magnetic resonance (n.1n.r.) analysis of the mixture of the two alcohols and by partition chromatography on a silica gel column. T o carry out the analysis it was necessary to synthesize the two alcohols by established procedures and t o exainine their physical properties. 9-Xantheneinethanol was prepared by the method of Anet and Bavin (1) and 10,l 1-dihydrodibenz[b,f]oxepin-lO(l1 ,H)-01 by borohydride reduction of the corresponding oxepinone, which was prepared by the method of kIanslte and Ledinghain (8). The isomeric tertiary alcohol, 9-methyl-9-xanthenol, a possible product of this reaction, was also prepared (9), but its properties were such that its presence in the alcoholic fraction from the Demjanov reaction is precluded. We found that, when the tertiary alcohol was placed on an alumina column and chloroform applied t o the column, the recovered product was not the alcohol. The product showed no hydroxyl absorption in the infrared, and was not further examined.T h e foregoing results show tha...
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