A. Jilale et al., SYNTHESIS OF CYCLOPENTATHIOPHENACETIC ACID-DERIVATIVES - REACTIVITY OF METHYL OXO-4,5-DIHYDRO-6H-CYCLOPENTA[B]THIOPHEN-4-ACETATE, Journal of heterocyclic chemistry, 30(4), 1993, pp. 881-885
Oxodihydrocyclopentathiophenacetic acids 4, 5 and 6 were synthesized f
rom suitable 2- or 3-formylthiophenes. Reactivity of the carbonyl grou
p or the carboxylic group of these bicyclic systems was investigated.
The Beckmann rearrangement of methyl ino-4,5-dihydro-6H-cyclopenta[b]t
hiophen-4-acetate 12 is an interesting route to methyl o-4,5,6,7-tetra
hydrothieno[2,3-c]pyridin-4-acetate (13).