Dibenzylidene succinates

P. A. Davidse, J. L. M. Dillen, A. M. Heyns, T. A. Modro, and P. H. van Rooyen, Photochromic systems. Part 1. Structural and spectroscopic study of photochemically active products of Stobbe condensation. 2,3-dibenzylidene-succinic acid and its anhydride, Can. J. Chem., 68, 741-746 (1990). 

Dibenzylidene succinic acid derivatives are examples of substrates with a direct link between the a-carbons. Voltammetry of dimethyl dibenzylidenesuccinate shows two reduction peaks separated by 200 mV, and preparative-scale reduction under a variety of conditions gave none of the cyclobutane derivatives expected from intramolecular cyclization. Monomeric products (2 F or 4 F depending on the working potential) were found together with varying amounts of oligomers [122],... 

Dihydronaphthalenes can be obtained by cyclization of. E, -dibenzylidene succinates 1. The stereochemistry of the products depends on the cyclization process. Thus, in the presence of light, ring closure in 1 leads exclusively to 1,2-cis-dihydronaphthalenes, whereas the cyclization in the presence of aeid yields the... 

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