Santos, Clementina M.M.Silva, ArturCavaleiro, José2011-04-042011-04-042003Santos, Clementina; Silva, Artur; Cavaleiro, José (2003). Synthesis of new hydroxy-2-styrylchromones. European Journal of Organic Chemistry. ISSN 1434-193X. 23, p. 4575-45851434-193Xhttp://hdl.handle.net/10198/3932http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=5&SID=V1M67gPH3IpI7j5a98j&page=1&doc=1&colname=WOSHydroxy-2-styrylchromones 5a−i were prepared by debenzylation of benzyloxy-2-styrylchromones 3a−i, which were synthesised by the Baker−Venkataraman method. The last step of this method, the cyclodehydration 5-aryl-3-hydroxy- 1-(2-hydroxyaryl)-2,4-pentadien-1-ones 2a−i, was carried out with a catalytic amount of iodine, or p-toluenesulfonic acid, in DMSO. Benzyloxy-3-cinnamoyl-2-styrylchromones 4a−f were obtained as by-products in both procedures, but the latter procedure gave benzyloxy-2- styrylchromones 3a−i in better yields. The structures of all new compounds were established by extensive NMR studies.engRearrangementsCyclizationsProtecting groupsHeterocyclesjournal article10.1002/ejoc.200300468