The present invention relates to a 1-halo-2,6,14-trimethyloctadecane compound of the following general formula (1), wherein X 1 represents a halogen atom. The present invention further relates to a process for preparing a 5,13,17-trimethylalkane compound of the following general formula (4), wherein n represents an integer of 14 to 18, the process comprising converting the aforesaid 1-halo-2,6,14-trimethyloctadecane compound (1) into a nucleophilic reagent, 2,6,14-trimethyloctadecyl, of the following general formula (2), wherein M 1 represents Li or MgZ 1 , and Z 1 represents a halogen atom or a 2,6,14-trimethyloctadecyl group, and subsequently subjecting the nucleophilic reagent, 2,6,14-trimethyloctadecyl compound (2), to a coupling reaction with an electrophilic alkyl reagent (3) of the following general formula (3), wherein X 2 represents a halogen atom or a p -toluenesulfonyloxy group, and n is as defined above, to obtain the aforesaid 5,13,17-trimethylalkane compound (4).