J. Profitt, T. Jones, D. Watt
1975
Citations
0
Influential Citations
19
Citations
Journal
Synthetic Communications
Abstract
Abstract Many antibiotics of the anthracycline family1 possess structures for which 3-methoxyphthalic anhydride (1) would be a suitable synthon2 in a total synthesis. A classic synthesis of (1) has employed 3-nitrophthalic acid3 but, in our hands, proceeded in low overall yield. Recent syntheses have utilized the Diels Alder reaction of dimethyl acetylenedicarboxylate (2) with 1-methoxy-1,3-cyclohexadiene,4 1,4-diacetoxybutadiene,5 2-acetoxyfuran,6 2-methoxyfuran7 or furan8 to obtain 3-hydroxyphthalic acid or a derivative. We now wish to report a convenient Diels-Alder synthesis of (1) from 3-methoxy-2-pyrone (3).