Process for the production of compounds useful in perfumery

A process for preparing an isochroman derivative having a structure selected from the group consisting of ##STR25## comprising the steps of reacting a hydrocarbon reactant which is an indane or tetrahydronaphthalene derivative having a structure selected the group consisting of:

• ##STR26## with propylene oxide in the presence of a solvent consisting essentially of at least one aliphatic saturated C.sub.5 -C.sub.10 hydrocarbon, said, aliphatic saturated hydrocarbon being halogen-free, at a temperature between -20.degree. C. and -5.degree. C. in the presence of an aluminum chloride catalyst;
• the weight ratio of the aliphatic saturated hydrocarbon to the indane or tetrahydronaphthalene derivative being from 1:10 up to 10:1;
• the mole ratio of aluminum chloride to propylene oxide being from 1:1 up to 2:1;
• the mole ratio of indane or tetrahydronaphthalene derivative to propylene oxide being from 1:1 up to 10:1;
• followed by addition of a lower C.sub.1 -C.sub.6 alkanol at a temperature of -20.degree. C. to 0.degree. C.;
• the mole ratio of aluminum chloride to C.sub.1 -C.sub.6 alkanol being from 2:1 up to 1:2;
• followed by addition at a temperature of from 20.degree. C. up to 80.degree. C. of a formaldehyde equivalent having the structure:
• R'.sub.11 --O--CH.sub.2 --O--R'.sub.11
• wherein R'.sub.11 represents C.sub.1 to C.sub.6 alkyl, or paraformaldehyde;
• and then quenching the resulting reaction mass by pouring it into water.