Hydrophenanthrene group

The seasonal variations of the alkaloids and the areas of occurrence of F. officinalis and M. microcarpa have been studied (217, 839). A similar paper was devoted to P. somniferum (513, 840) an analysis revealed that a general accumulation of alkaloids, especially the hydrophenanthrene group, occurred one day after the flower had opened. This coincides with the peak of the pollination period. At that period, besides the principal opium poppy latex alkaloids (morphine, codeine, thebaine, papaverine, and narcotine), several other Dragendorff positive compounds were detected. The lysosomal property and accumulation of the alkaloids in vacuoles of Chelidonium majus have been described (841). 

The bulky hydrophenanthrene group of the rosin increases the glass transition temperature of the modified PCL by greater than lOOX (2). 

However, one should not be too optimistic about these interesting possibilities. These two potential reaction sites are very much shielded by the bulky hydrophenanthrene group and the cyclic anhydride ring of the maleic anhydride residue. The probability of reaction of these groups is, therefore, not very high. Ordinary reaction conditions may not be adequate extreme or unusual conditions... 

Composition. Rosin is primarily a complex mixture of monocarboxyUc acids of alkylated hydrophenanthrene nuclei. These constituents, known as resin acids, represent about 90% of rosin. The resin acids are subdivided into two types, based on their skeletal stmcture. The abietic-type acids contain an isopropyl group pendent from the carbon numbered 13. The pimaric-type acids have a methyl and vinyl group pendent from the same carbon atom. Figure 1 shows the stmcture of typical resin acids abietic acid, C2QH2QO2 (1) is predominant. The remaining 10% of commercial rosin consists of neutral materials that are either hydrocarbons or saponifiable esters. These materials are derived from resin acids by decarboxylation or esterification. 

Figure 12.5 Cholesterol ester. Cholesterol is a derivative of the cyclopentanoper-hydrophenanthrene condensed ring system and is therefore a member of the group of compounds called steroids. It often occurs esterified at position 3 with a long chain fatty acid, which may be saturated or unsaturated and commonly contains 16 or 18 carbon atoms. Steroids that form esters in this way are more correctly called sterols.

A classical application of cyclopropane rings in "reactivity inversion", in which a previously negatively polarised y-carbon atom (see 29) to a carbonyl group is inverted by formation of a cyclopropane ring (30) and is then intramolecularly attacked by a nucleophilic aromatic ring, is found in the synthesis of hydrophenanthrene system 11 (Scheme 5.19) developed by Stork in 1969 [21]. 

Dehydroabietic acid 1, the main resin acid of disproportionated rosin, is a readily available hydrophenanthrene derivative and a useful starting material for the synthesis of industrial and/or physiologically important products (1), by introduction of suitable substituents in the aromatic ring, such as the nitro or amino groups. 

The mechanism in Scheme 19 is somewhat speculative, and relies heavily on the assumption that axial attack of solvent is more energetically favorable than equatorial attack of solvent on carbocations similar in structure to 64. However, the stereochemistry of acid-catalyzed hydrolysis of two diastereomeric hexa-hydrophenanthrene 9,10-epoxides (65 and 67) provides support for this proposal. These two epoxides contain transfused cyclohexane moieties that restrict the geometry of each epoxide to a single conformation. Reaction of 65 with H+ yields a single carbocation conformation 66, in which the hydroxyl group is forced to occupy an axial position (Scheme 20). 

A (molar weight M=256) results from the simple elimination of the methylcarboxylate group, B (M=174) is probably isopropyl-1,2,3,4-tetra-hydronaphtalene, C (M=222) and D (M=224) are isopropyl-hydrophenanthrenes. Cymenes were also observed, which shows that deisopropylation of 1 occurs through isopropyl transfer into toluene. Two types of acid mechanism have been proposed to explain alkyl transfer [12]. The first which is the more likely occurs through alkyl transfer from a protonated molecule of 1 to toluene... 

Employing labeled A-norlaudanosolines it has been shown that it is the precursor of papaverine, the hydrophenanthrene alkaloids (IIB), and reticuline (203) in Papaver somniferum. Laudanosoline itself was found to be incorporated into berberine in Berberis japonica, the carbon atom 8 of the latter base originating from the A-methyl group of the former (198). 

The 17-ketosteroids are defined as compounds of the cyclopentanoper-hydrophenanthrene series which possess a carbonyl group at carbon 17. 

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