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Report | Regular issue | Vol 14, No. 5, 1980, pp.657-660
Published online, 1st January, 1970
DOI: 10.3987/R-1980-05-0657
A One Pot Reaction Involving Hydrolysis-Reduction of Biphthalylidene in an Alkaline Medium

Masashi Tashiro,* Tsuyoshi Sumida, and Gouki Fukata

*Research Institute of Industrial Science, Faculty of Engineering, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan


The hydrolysis of biphthalylidene (2) in a varying alkaline medium afforded selectively 2,2’-dicarboxybenzoin (3) or 5,5’-dihydro-5-oxo-diphthalylidene (4) in good yields depending upon the conditions used. In one pot reaction involving hydrolysis of 2 followed by reduction with Raney-alloys, 4b,10b-dihydrobenzopyrano[4,3-c]benzopyrano-6,12-dione (9) was almost selectively obtained in good yields. In the case of the combination of hydrolysis in 10% KOH aq and Al-Ni alloy reduction, 2,2’-dicarboxybibenzyl (8) yielded in 51% as a sole product.