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.