PURPOSE: To obtain the title compound useful as perfume in high purity, in high yield and industrially by subjecting 2,5,5,8a-tetramethyl-1-(2-hydroxyethyl)-2- hydroxydecalin to contact reaction with a zinc halide in an organic solvent.

CONSTITUTION: A compound shown by formula 2 is subjected to contact reaction with a zinc halide such as zinc bromide, zinc iodide, zinc fluoride or zinc chloride, especially zinc chloride in an organic solvent such as dichloromethane, carbon tetrachloride, toluene, benzene, ether or tetrahydrofuran preferably at about -10°C to +50°C for about 8-20 hours to give the aimed compound shown by formula 1 useful as a perfume substance having amber-like fragrance by ready operation in high purity and in high yield and inexpensively. The raw material can be readily synthesized by treating sclareol with an oxidizing agent and reducing obtained noranbrinolide.