Phenanthrene, natural derivatives

Chemical Class-. Natural opium alkaloid phenanthrene derivative... 

Brand Name(s) Astramorph PF, Avinza, DepoDur, Duramorph PF, Infumorph, Kadian, M-Eslon, MS Contin, MSIR, MS/S, Oramorph SR, Rapi-Ject, RMS, Roxanol, Roxanol-T Chemical Class Natural opium alkaloid phenanthrene derivative... 

Most phenanthrene alkaloids are easily synthesized by degradation of the corresponding aporphines. Many phenanthrenes were first prepared as aporphine derivatives for characterization or in the course of structural studies, and only later were they found in nature. Although the ready availability of most aporphines from natural sources makes this strategy very simple, it often does not constitute a formal total synthesis, and some approaches from simpler compounds have been published (29,105). Degradation of the morphine alkaloid thebaine (151) gives rise to a number of unnatural phenanthrenes (93,94,102, 104,113). 

Fluorene has been reported to afford the 3,9a-dihydro product, but it is almost certain that this is the 2,4a-dihydro isomer (55 = 1) by analogy with biphenyl. 9,10-Dihydrophenanthrene (56) is reduced as expected to (55 n = 2), but spontaneously reverts to the starting material on standing. These systems do not require the presence of alcohol for reduction and it is consequently possible to alkylate the intermediate anions with alkyl halides, as (56) gives (57). These products are much more stable and structural analysis is simplified accordingly oxidation of the doubly allylic methylene occurs readily to afford the dienone (58 Scheme 7). Dienones of this type have potential as intermediates for the synthesis of natural products. Anthracene and phenanthrene are both readily reduced in the central ring to form the 9,10-di-hydro derivatives as might be expected, but to avoid further reduction it is necessary to have an iron salt present. Further examples are reviewed elsewhere. ... 

Greiner A.C., Spyckerelle C., Albrecht P. (1976) Aromatic hydrocarbons from geological sources-I. New naturally occurring phenanthrene and chrysene derivatives. Tetrahedron 32, 257—60. 

Coal tars are by-products of the carbonization of coal to produce coke and/or natural gas. Physically, they are usually viscous liquids or semi-solids that are black or dark brown with a naphthalene-like odor. The coal tars are complex combinations of polycyclic aromatic hydrocarbons, phenols, heterocyclic oxygen, sulfur, and nitrogen compounds. By comparison, coal tar creosotes are distillation products of coal tar. They have an oily liquid consistency and range in color from yellowish-dark green to brown. The coal tar creosotes consist of aromatic hydrocarbons, anthracene, naphthalene, and phenanthrene derivatives. At least 75% of the coal tar creosote mixture is polycyclic aromatic hydrocarbons (PAHs). Unlike the coal tars and coal tar creosotes, coal tar pitch is a residue produced during the distillation of coal tar. The pitch is a shiny, dark brown to black residue which contains polycyclic aromatic hydrocarbons and their methyl and polymethyl derivatives, as well as heteronuclear compounds... 

Naturally, rigidly held stilbene moieties yield phenanthrene derivatives on irradiation, and the cyclization of 9-benzylidenexanthenes and 9-benzylidene-thioxanthenes yields compounds of type (72) from both sunlight and u.v. 

Stermitz, RR. et al 1983. New and old phenanthrene derivatives from Onetdium ceboHeta, a peyote replacement plant "Journal of Natural Products 417—423. 

If the cationic intermediates for a substitution are close in energy, little selectivity is expected and a mixture of products is predicted. An illustration is the nitration reaction of phenanthrene, which gave five products 345 (6%), 346 (23%), 347 (7%), 348 (27%) and 349 (37%).Although substitution at C9 is preferred, a complex mixture is obtained that may be very difficult to separate. Substitution at several positions is a common occurrence for substitution reactions of polycyclic aromatic derivatives, although the product distribution is usually influenced by the nature of the catalyst and by the reaction conditions that are used. 

The most important experimental fact, however, reported for any of the miscellaneous bases concerns the unnamed base recently (90) isolated, which accompanies delphinine and staphisine in D. staphisagria. This base, which may not be correctly formulated, on dehydrogenation over selenium jdelds a crystalline hydrocarbon (CisHie), the ultraviolet absorption spectrum of which indicates the presence of a phenanthrene structure. The fact that the presence of a phenanthrene system can be established both in this new base and in staphisine, i.e., in both minor alkaloids accompanying delphinine, whilst delphinine itself does not readily yield a phenanthrene derivative on dehydrogenation (70), should stimulate further research in this field. If the reason for this difference in behavior can be ascertained, it should permit a better imderstanding of the nature of the polycyclic skeleton present in the atisines and in the aconitines and result in a great advance towards the complete elucidation of the structures of the Aconitum and Delphinium alkaloids. 

Pd-catalyzed cocyclization of arynes with alkynes also proceeds smoothly. Yamamoto obtained phenanthrene derivatives exelusively in good yield, regardless of the electronie nature of the alkynes using Pd(OAe)2 and P(o-Tol)3. The reaction of 251 with 4-octyne gave rise to the phenanthrene 263 [82], Similarly, Perez carried out the reaction of benzyne with electron-dehcient alkynes such as dimethyl acetylenedi-carboxylate (DMAD) (264), and obtained the phenanthrene 265 as the main product using Pd(PPh3)4. On the other hand, when Pd2(dba)3 was used, the naphthalene derivative 266 was the main produet [83]. 

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