T. Horaguchi, T. Shimizu, T. Abe
Mar 1, 1976
Citations
0
Influential Citations
7
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
A compound, 6-methoxy-2a,3,4,5-tetrahydro-2H-naphtho[1,8-bc]furan-5-one (XX), was prepared in a 72% yield by heating 3-(5-methoxy-2,3-dihydrobenzofuran-3-yl)propionic acid (XIX) with polyphosphoric acid. However, when 3-(5-methoxybenzofuran-3-yl)propionic acid (IX) or 3-(2-benzoyl-5-methoxybenzofuran-3-yl)propionic acid (XIII) were treated with polyphosphoric acid, the product was 7-methoxy-2,3-dihydro-1H-cyclopenta[b]benzofuran-3-one (XI) rather than the corresponding naphtho[1,8-bc]furan derivatives, Also, neither naphtho[1,8-bc]furan nor cyclopenta[b]benzofuran derivatives were obtained from 3-(2-benzyl-5-methoxybenzofuran-3-yl)propionic acid (XIV) or 3-(2-ethyl-5-methoxybenzofuran-3-yl)propionic acid (XVII).