M. G. Bogdanov, M. Palamareva
Mar 8, 2004
Citations
0
Influential Citations
28
Citations
Journal
Tetrahedron
Abstract
Abstract Homophthalic anhydride ( 1 ) reacts with wide variety of aromatic aldehydes, in the presence of chloroform and DMAP (N,N-dimethyl-4-amino-pyridine) at room temperature, to give in high yields cis- and trans-1-oxo-isochroman-4-carboxylic acids. Under these conditions, the trans-isomer is predominant and formation of Perkin-type products was not observed in contrast to the reaction carried out in the presence of pyridine. The unexpected trans-6-oxo-11-thiophen-2-yl-11,12-dihydro-6H-dibenzo[c,h]chromene-12-carboxylic acid methyl ester ( 8 ) was isolated when the reaction between 1 and thiophene-2-carbaldehyde was carried out in pyridine.