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COMMUNICATIONS TO THE EDITOR
Vol. 83
I n a number of instances,a ready halogenation of chlorins has been observed, but it has been assumed that the reactions involve substitution a t the 7 or 8 positions. Although these cases deserve reinvestigation in detail, there can now be little doubt that the views previously advanced are erroneous, and that the products of these reactions are y or 6 halogenated derivatives. This work was generously supported by the National Institutes of Health.
gas Chromatography in 7370 yield. The u!traviolet absorption spectrum of this derivative had3‘ ::X: 370 nip as anticipated ( c f . 2,4-dinitrophenylhydrazone of acetylcyclopropane: Xzt:’3 371 m/i5). ‘The n.m.r. spectrum of 111 showed absorption due to tn-o non-equivalent hydrogens of the cpc1oprc)pane methylene at T cu. 8.9 (lowered by conjugation with the carbonyl). Unambiguous confirmation of the structure of our [i),1,4]bicycloheptanone-2 was obtained by an independent synthesis. Catalytic hydrogenation (3) (a) H. Fischer and K. Herrle, A n n . , 530, 236 (1937); Ib) H Fischer and E. A . D i d , ibid., 547, 234 (1941); ( c ) H . Fischer, 15. (rhodium-charcoal) of m-hydroxybenzoic acid, then Kellermann and F. B a l i t , Bar., 76, 1778 (1942); ( d ) H. Fischer and esterification and oxidation with chromic acidF. Ba161. A n n . , 655, 81 (1943); ( e ) H. Fincher and F. Gerner, i b i d . , acetone-sulfuric acid, gave the known6 ethyl-3-oxo559, 77 (1948). cyclohexanecarboxylate. Ketalization with ethCONVERSE MEMORIAL LABORATORY HARVARD UNIVERSITY R . B. ~ ~ i O O D W A R D ylene glycol and reduction with lithium aluminum CAMBRIDGE 38, MASSACHUSE’TTS \“KO SKARIC hydride gave the ketal of 3-oxo-cyclohexanernethanol (IV) b.p. 116-124’ (0.2 mm.) (found: C, 62.32; H. 9.43). Reaction of IV with p-toluenesulfonyl INTRAMOLECULAR CYCLIZATION OF chloride in pyridine and deketalization with aqueUNSATURATED DIAZOKETONES ous methanolic hydrochloric acid produced the Sir: tosylate of 3-oxocyclohexanemethanoI (V) ; 2,4The intermolecular reaction of diazoketones with dinitrophenylhydrazone, m.p. 118” (found : C, olefins has been described by Sorm and his col- 52.21; H, 4.90j: laborators. Cyclization of the keto tosylate V with sodium So far as we are aware the intramoleculur counter- hyd;ide7 in tetrahydrofuran gave, in low yield, the part of this reaction has not yet been reported. bicyclic ketone I11; 2,4-dinitrophenylhydrazone, We were interested in exploring the feasibility of 1n.p. 162-163‘, undepressed by the sample from such a reaction for the synthesis of [0,1,4]bicyclo- the diazoketone decomposition. The infrared heptane derivatives and have succeeded in synthe- spectra of the ketones made by the two routes were sizing [0,1,4]bicycloheptanone-2 (111), one of the essentially identical, and so mere the characteristic simplest substances that might be prepared by the n.m.r spectra. “A6 diazoketone” route. 0 CH?=CI-ICH2CH2(:H2CF!?CO1H -* Pure 5-hexenoic acid (I) was prepared from 4I1 I C~12=CH-(CH2)4-C-CHN2 penten-1-o12 via the corresponding bromide and I1 nitrile.3 The unsaturated acid was transformed into its acid chloride by reaction with oxalyl chloride in benzene at room temperature, and the acid chloride was converted, without distillation, into its diazoketone (11). The diazoketone (5 g.) was refluxed for eleven hours in 250 ml. of cyclohexane in the presence of 0.5 g. of copper bronze. Shorter time led to incom(5) L). H. R. Barton, T. Bruun and A. S. Lindsey, J . Chem. SOL.. plete reaction as evidenced by the presence of 2210 (1952). (6) G. K. Komppa, T. Hirn, W. Rohrtnann and S. B e c k m a n n , diazoketone in the mixture (infrared). Distillation n . , 621, 242 (1936). gave 2.5 g. of a fraction boiling a t 74-76’ (8 mm.). A n(7) Cf.X. A. Nelson and G. A. Mortimer, J . Org. Cham., 24, 1146 This consisted mainly (see below) of the desired (1967). [O, 1,4]bicycloheptanone-2 but was not completely THECHANDLER LABORATORY GILBERTSTORK homogeneous, as shown by the presence of two COLUMBIA UNIVERSITY JACQUELINE F I C I N 1 absorption bands in the carbonyl region of the in- XEWYORK27, NEWYORE RECEIVED OCTOBER 20, 1961 frared and by gas chromatography. The latter (5 f t . silicone column, 150’) showed the product to be contaminated with about 20% of a substance with THE STRUCTURE OF INDOLMYCIN absorption at 5.85 p in the infrared. The pure I11 from the chromatogram had its carbonyl absorption Sir: We wish to propose structure 1 for indolmycin, at 5.96 p , XE2” 220 mp and 275 mp ( e 34),4 and gave its 2,4-dinitrophenylhydrazone,m.p. 158’ previously designated PX-155A.1~2 This antibiotic (calcd. for C13H14N404: C, 53.79; H, 4.86; N, 19.30. is the first example of a new structural type. Found: C, 53.96; H, 4.90; N, 19.47). The same Indolmycin was isolated from a culture of Strep2,4-dinitrophenylhydrazonewas obtained before tomyces albus’ and some of its properties have been d e ~ c r i b e d . ~The , ~ compound has the molecular (1) F. Sorm and J. Novak, Collection Ceechoslou. Chem. C o m m r n s . , and an ultraviolet absorption 2 2 , 1836 (1957); F . Sorm and J. Ratusky, ibid., 23, 467 (1958); F. formula C14HI6N3O2 Sorm and J. Novak, ibid., 13, 1126 (1958). spectrum closely resembling that of tryptophan. (2) R. Paul a n d H. Normant, Bull. soc. chirn., 484 (1943). (3) F. B. LaFurge, N. Green and W. Gersdorff, J . A m . Chenz. SOC., 7 0 , 3709 (1948). (4) Cf. A. Sandoval, G. Rosenkranz a n d C. Djcrds5i. ;bid., 73, 2383 (195 1J.
I I ) W. S. Marsh, A. L. Garretson and E. hf Wesel. Antibiotics and Chemofherapy, 10, 316 (1960) (2) K.V. Rao, ibid., IO, 312 (1960). (3) A. R. English, T . J. McBride, ibid., in press.
