The present invention concerns the novel odorant 1,1,2,3,3,6-hexamethyl-4,5,6,7-tetrahydro-5-indanone, I, a process for the manufacture of I, novel intermediates used in the process and fragrance compositions containing I. ##STR1## The process for the manufacture of 1,1,2,3,3,6-hexamethyl-4,5,6,7-tetrahydro-5-indanone comprises hydroborating 1,1,2,3,3,6-hexamethyl-4,7-dihydroindane and oxidizing the hydroboration product to 1,1,2,3,3,6-hexamethyl-4,5,6,7-tetrahydro-5-indanone, or reductively alkylating, especially methylating, 5-nitro-1,1,2,3,3,6-hexamethylindane and converting the resulting 5-dialkyl-amino-1,1,2,3,3,6-hexamethylindane into 1,1,2,3,3,6-hexamethyl-4,5,6,7-tetrahydro-5-indanone by reduction of the benzene ring and hydrolysis of the resulting enamine.