P-Truxinic acid

Diquercetin 3-galactoside ester of tetrahydroxy-p.-truxinic acid (monochaetin, 13.6) Monochaetum multiflorum leaves Melastomataceae 360... 

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)...

After 2 days P-monomer after 6 days mainly 2,2 -diethoxy-P-truxinic acid... 

Although earlier claimed to be unsuccessful, the photochemical reaction of stilbene with fumaric ester has now been used to synthesize p-truxinic acid (212). 

The photodimerisation of cinnamic acid can be controlled by irradiation of its double salts with certain diamines in the solid state. Thus, the double salt crystal of cinnamic acid and o-diaminocyclohexane gave upon irradiation in the solid state, P-truxinic acid as the major product (Scheme 129)P ... 

Coates et al. used stacking interactions in the phenyl-perfluorophenyl system to direct co-crystal-lization of mixed stilbene and cinnamic acid co-crystals, thereby directing the formation of the mixed P-truxinic acid derivative in very high yield. Ito has recently reviewed the solid-state organic photochemistry of mixed crystals. " ... 

Photodimerization of trans-cinnamic add 47 is controlled by the formation of a double salt with diamines.It is known that 47 gives a-truxUlic add 49 efiidently on irradiation. The double salt crystals of 47 and ds-1,2-cydohexanediamine 48, on the other hand, yield P-truxinic acid 50 predominantly. 

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