Truxillic acid

The acetylation of isotripiperideine by means of a ketone in nonpolar media affords a compound which decomposes in acidic media to piperideine and a monoacety.l derivative of the enamine form of tetrahydro-anabasine (195). This monoacetyl derivative is identical with the alkaloid amodendrine (312). A similar acylation with cinnamoylchloride affords the alkaloid orensine (196) (313), the optically active form of which is the natural alkaloid adenocarpine (314). The hydrolysis of alkaloid santiaguine gives a-truxilic acid (314). 

Although the ultimate criterion is, of course, nonsuperimposability on the mirror image (chirality), other tests may be used that are simpler to apply but not always accurate. One such test is the presence of a plane of symmetry A plane of symmetry (also called a mirror plane) is a plane passing through an object such that the part on one side of the plane is the exact reflection of the part on the other side (the plane acting as a mirror). Compounds possessing such a plane are always optically inactive, but there are a few cases known in which compounds lack a plane of symmetry and are nevertheless inactive. Such compounds possess a center of symmetry, such as in a-truxillic acid, or an alternating axis of symmetry as in 1. A... 

The photodimerization of 3-methyl-4-nitro-5-styrylisoxazoles 137 has been studied in the solid state82. Truxillic acids 139 are prepared by the oxidation of the photodimers 138 (equation 69). 

The nature and amounts of low molecular weight phenolic constituents in cell walls of graminaceous plants (grasses and cereals) are reviewed and relationships discussed between these constituents and wall biodegradability. The formation in cell walls of 4,4 -dihydroxy-truxillic acid and other cyclodimers of p-coumaric and ferulic acid is suggested as an important mechanism for limiting the biodegradability of wall polysaccharides. 

Keywords cinnamic acid derivative, [2+2]photodimerization, a-truxillic acid, cyclobutane... 

A white powder (158 mg) obtained from photolysis of the double salt 2 was fractionally recrystallized by using 10 mL of methanol, resulting in the isolation of pure colorless plates of the 1 1 (from NMR) e-truxillic acid tram-1,2-diaminocy-clohexane salt yield 57 mg, mp 146-150 °C. In addition, 2 mg of white crystals of the 1 1 -truxillic acid trails-1,2-diaminocyclohcxane salt contaminated with a small amount of die above double salt was obtained. Free <5-truxillic acid was recovered by dissolving 3 mg of the double salt in 1 mL of water, followed by acidifying the solution with 1 M HC1 to pH 1, as white needles (1.5 mg), mp 200-202 °C (lit. mp 192 °C). 

Scheme 3 Photodimerisation of trans-cinnamic acid (9) and three of the possible diastereomers, the a-truxillic acid (10), the p-truxinic acid (11) and the 5-truxinic acid (12)...

Diethoxy-a-truxillic acid 36% 2,2 -diethoxy-a-truxillic acid 32% 2,2 -diethoxy-P-truxinic acid... 

Stdrmer, H. and Laage, E. (1921). Truxillic acids. (III). Natural and artihcial truxihic and truxinic acids. Berichte, 54B, 77-84. [234]... 

In contrast to solutions, solid drugs have a fixed conformation resulting in topochemical reactions. The majority of photoreactions in the solid state, described in the literature, deal with lattice-controlled examples and photodimerizations. A precondition for these reactions is the parallel position of the double bond of two adjacent molecules in the crystal lattice as shown by the example of the trimorphic, frans-cinnamic acid. Irradiation of the a- and the 5-modifications causes the formation of a-truxillic acid and (i-truxinic acid, respectively, whereas the y-modification is photostable due to the distance of the double bonds fixed by the lattice (Fig. 8) (10). 

On the other hand, kitol is resistant to treatment with active manganese dioxide therefore, it appears that kitol has no a,j3-unsaturated hydroxyl groups. From these facts and also from a comparison of the relation between cinnamic acid and its photodimer (truxillic acid) with the relation between vitamin A and kitol, the author presumed that kitol is a dimer of vitamin A and has a cyclobutane ring formed by the carbon atoms in position 13 and 14. A probable structure is ... 

Vellturno and Griffin have used anodic decarboxylation as a preparative route to small ring compounds. Electrolysis of a-truxilic acid (24) produced the cis-lactone (25) as... 

Photochemical dimerization of the diene (160) has been carried out in the solid state. The styry1isoxazoles (161) are also photoreactive and yield (2+2)-dimers. Oxidation of these affords the a-truxillic acids derivatives (162). The photochemical dimerization of (163) has been reported to afford a cyclobutane derivative when irradiated in the solid phase. A detailed review has surveyed the conformation effects influencing photochemical solid state reactions. ... 

The conversion of the benzene ring in benzene homologues to carboxylic groups is encountered rarely and has hardly any preparative value. One example involves the treatment of a-truxillic acid with ozone and subsequent oxidation with hydrogen peroxide (equation 155) [109]. 

Draw the five stereoisomers of truxillic acid (85) why is none chiral (see Mislow17) ... 

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