Vp. Anufriev et al., A CONVENIENT METHOD FOR THE SELECTIVE ALKYLATION OF BETA-OH GROUPS OF2(3)-HYDROXYJUGLONES AND HYDROXYNAPHTHAZARINES, Synthetic communications, 27(1), 1997, pp. 119-126
Trimethyl- and triethylorthoformates have been used for the selective
alkylation of beta-OH groups of 2(3)-hydroxy-3(2)-alkyljuglones, 2-hyd
roxy-3-alkyl-, 2-hydroxy-3-chloro-, and 2,3-dihydroxynaphthazarines (1
a-o,3,4). In most cases the corresponding alkoxy compounds (2a-q,5,6)
were obtained in good yields. However, when 2-hydroxynaphthazarine (1p
) was used, the formation of monomethineoxonol derivative (9) as the p
rincipal product took place.