Demethylation of asymmetically substituted 2,6-dimethoxybenzaldehydes with magnesium iodide etherate regioselectively single 6-methoxysalicylaldehydes derived from the more unstable chelation. (C) 1999 Elsevier Science Ltd. All rights reserved.
Synthetic study for two 2<i>H</i>-chromenic acids, 8-chlorocannabiorcichromenic acid and mycochromenic acid
Two 2H-chromenes having a fully substituted benzene ring, 8-chlorocannabiorcichromene (1) and mycochromenicacid (2), were synthesized by a condensation of salicylaldehydes with isopropylidenemalonate or the thermal cyclization of corresponding propargyl ethers.