A new metabolite has been isolated from the fungus Monochaetia compta. The properties and reactions of the metabolite suggest that it is 6,8a-dihydro-4-acetyI-8-methyl-6-oxo-7(3-methyJ-2-oxo)-pentyl-1 H-2-benzopyran-1-one ( 2 4 .Canadian Journal of Chemistry, 48,3654 (1970) A fungus (PRL 1754) was isolated from wild rose hips (Rosa acicularis Lindl.) and identified as Monochaetia compta (or possibly Cryptostictis cynosbati (Fckl) Sacc. (Melanconiales) (1)). The only member of the Melanconiales for which a metabolite has been reported (2) is Gloeosporum musarum (Cke et Mass.) which produced the carotenoid canthaxanthin (4,4'-diketo-P-carotene) (3). The present fungus deposited white crystals m.p. 202.5-203.5' in potato dextrose agar cultures. Constancy of m.p., t.1.c. and p.rn.r. spectroscopy, and mass spectral analysis attested to the homogeneity of the new metabolite, which analyzed for C,,H,oO,. We propose the name monochaetin for this compound and describe work which suggests that its structure is represented by 2a.The p.m.r. spectrum of monochaetin in deuterochloroform solution ( Fig. 1) was interpreted as follows: T 9.03 (3H), a triplet ( J = 7 Hz), CH,CH2-; 8.3 (2H), a multiplet CH3CH2-CH-; 6.81 (lH), a sextet CH3CH,CHCH3; 8.87 (3H), a doublet ( J = 6 Hz) CH3CH,-CHCH,. Double irradiation experiments confirmed the appropriate mutual couplings of this group. Since the rnethine sextet occurred at a low field position it follows that the next carbon atom was not substituted by hydrogen but by an electronegative atom or group. In view of the i.r. spectrum (see below) a carbonyl group seemed the most probable. A singlet T 8.67 (3H) was assigned as and a singlet at T 7.87 (3H) was interpreted as being due either t o a methyl ketone or to an 0-acetyl group. Chemical tests confirmed that this was a methyl ketone; no acetic acid could be detected after monochaetin was hydrolyzed with sulfuric acid but iodoform was generated by a n alkaline solution of iodine and potassium iodide. The remaining peaks were at T 6.25 (lH), doubledoublet (J's = 2 and 13 Hz); 5.90 (1 H), a doublet (J = 13 Hz); 4.72 (1 H), doublet ( J = 0.5 Hz); 4.00 (lH), singlet -CH=C' a very small \ ' coupling to the methyl group' at .r 7.87 was revealed by a sharpening of this peak on double irradiation at the frequency of the methyl group, so that the substitution of this double bond could be written .r 3.20 (1 H), double doublet (J's = 0.5 and 2 Hz).The i.r. spectrum of monochaetin (chloroform) had two sharp bands at 1788 and 1718 cm-' (Fig. 2), which could be assigned to an enollactone (or vinyl ester) and a saturated ketone, respectively. A third broad band at 1650-1640 cm-', together with the bands at 1605 and 1532 cm-' were interpreted as an a$-a'$'-dienone and an a,P-unsaturated ketone. The broad Can. J. Chem. Downloaded from www.nrcresearchpress.com by 54.202.27.70 on 05/11/18For personal use only.
The decomposition of the diazoniuni salt from 3-(0-ami1iobenzoy1)pyridine has been studied under various conditions. A competitive-type cyclization of an equi~nolar ~iiixture of the diazonium salts of 2-aminobenzophenone and 2-arnino-3'-nitrobenzophenone has also been carried out. The results are interpreted in ternis of a radical process in the copper-catalyzed reactions. I t is suggested t h a t the uncatalyzed thermal decompositions in aqueous acid s o l u t i o~~ give rise to a diradical cation interlnediate in equilibriu~n with the aryl cation.
Benzo[c]phenanthridine has been synthesized i n low overall yield b y t h e Pschorr cyclization o f t~ans-a-(4-isoquinoly1)-o-arninocinnarnic acid. T h e condensation o f 4-isoquinolylacetonitrile with o-nitrobenzaldehyde gave t h e cis-cinnamonitrile. T h e preparation o f a number o f intermediates is described.The benzo[c]phenanthridine ring system (I) is found in a number of alkaloids such as chelidonine, chelerythrine, and sanguinarine (1). A number of these and their derivatives have been synthesized (2-4) starting from an alicyclic system, the nitrogen-containing ring being built up in the course of the synthesis. Current interest in chelerythrine (111) stems from its synergistic effect in enhancing the cancer chemotherapeutic action of colchicinamide ( 5 ) . I t was decided t o develop a more flexible synthesis of the ring system which would permit the introduction of various substituents into the nucleus, and to use the Pschorr cyclization to achieve this end.There have been a number of attempts made to apply a Pschorr type of ring closure t o the synthesis of this ring system (6-8) but these failed in each case. The diazotization and subsequent decomposition of 2-amino-N-methylbenzo-1'-naphthalide (IV) was studied in detail by Hey and Turpin (9). No benzophenanthridone was formed, the only identifiable product being benzo-1-naphthalide, which results from the demethylation and deamination of IV. In the present work the cyclization of trans-a-(4-isoquinoly1)-oaminocinnamic acid (V) to 11, which would involve an internuclear attack onto a pyridine ring, has been studied.
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