An Improved Synthesis of 2,7-Dihydroxytropone (3-Hydroxytropolone)

Article abstract of DOI:10.1055/s-1986-31713

2,7-Dihydroxytropone is efficiently prepared from 2-methoxytropone by bromination with N-bromosuccinimide, reaction of the resultant 2-bromo-7-methoxytropone with acetyl trifluoroacetate in situ, and hydrolysis of the 2,7-diacetoxytropone thus obtained with aqueous acetic acid.The intermediacy of a 2-acetoxy-1-bromo-3-methoxytropylium salt in the acetoxylation step is suggested.