Abstract: A process is provided for preparing a substituted 2,3-dihydrobenzofuran of the general formula ##STR1## in which R.sub.a is hydrogen, halogen, alkyl, straight or branched having from 1 to 4 carbon atoms, aryl, alkaryl, --OH, --OR.sub.3, --N(R.sub.d).sub.2, where R.sub.3 and R.sub.d are alkyl, straight or branched having from 1 to 4 carbon atoms; R.sub.b is alkyl, straight or branched, having from 1 to 6 carbon atoms, aryl, alkaryl; and R.sub.c is hydrogen or the same as R.sub.b, by the rearrangement of a 1,1-bis(2-hydroxybenzene) alkyl and/or aryl-ethane, in the presence of catalytic amounts of a mineral acid or organic acid such as phosphoric, sulfuric or p-toluenesulfonic, at elevated temperatures from 180.degree. to 250.degree. C., and withdrawing the resulting products from the reaction mixture as they are formed. The starting 1,1-bis(2-hydroxybenzene) alkyl and/or aryl-ethane compounds may be obtained by the catalyzed reaction of a substituted biphenol with an aldehyde.

Abstract: Process for the preparation of 2,3-dihydro-2,2-dimethyl-7-benzofuranol, comprising the reaction between catechol or 4-tert.butyl catechol and isobutyraldehyde in the presence of catalytic amounts of at least one compound selected from the group consisting of the oxides, hydroxides, alcoholates and carboxylates of metals belonging to the Groups IA, IIA, IIB and VIIB of the Periodic System of the Elements and the subsequent reaction of rearrangement of the products which have been obtained, optionally previously removing one or more low-boiling components, in the presence of a compound having acidic properties, of an organic or a mineral nature. The product is useful in the synthesis of pesticides.