(1E,5E)-1-Iodopentadeca-1,5-diene is an intermediate in the synthesis of (4E, 8E)-Sphingadienine-C18-1-phosphate (S680680), which is an analogue of (4E, 14Z)-Sphingadienine-C18 (S680630), a sphingoid base of sea cucumber cerebroside that may have cytotoxicity activity against human colon cancer cells.