A-Truxilic 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... 

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

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... 

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). 

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]. 

The experimental proof for anisotropic far-reaching molecular migrations within crystals by AFM analysis is particularly important with the former standard of topochemistry the a-cinnamic acid 1 photochemistry to give predominantly a-truxillic acid 2 (Scheme 2.1.1). 

Figure 2.1.6 Trial plot of the resulting crystal packing as calculated from the published fractional coordinates and space group based on a 0.3-0.7 mm long crystal of a-cinnamic acid 1 after tail irradiation to give a claimed [25] 100% conversion to a-truxillic acid 2.

When hydrolyzed with acid santiaguine produces a-truxilic acid and a base CioHigNj which is hydrogenated catalytically to ajS -dipiperidyl. Consequently, the alkaloid is W,W -o-truxil-bis (tetrahydro-anabasine), and Costa and Bibas (110) have assigned to it the partial structure CCXV. 

General Considerations. Cinnamic acid solid state photodimerizations are the prototype for the topochemical postulate and reasoning [7], The a-modification of frans-cinnamic acid a-4 gives a-truxillic acid 5 (head-to-tail), while the /i-modification (/J-4) gives /i-truxinic acid 6 predominantly... 

Isomer (c = C6H5 a,d,e = H b,f = COOH), t -cocaic acid. Prepd by fusion of a -truxillic acid with KOH Hesse, Ann. 271, 180(1892). Needles from ether, mp 192. Freely sol in glacial acetic acid, abs alcohol, chloroform less sol in benzene practically insol in ligroin. 

The photochemistry of the fibre-forming acrylonitrile copolymers,252 the benzene-photosensitized depolymerization of a-truxillic acid,253 and the photostability of coloured polymeric materials 254 have been discussed. 

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