Starting from (all-Z)-icosa-5,8,11,14,17-pentaenoic acid (EPA). syntheses o
f the naturally occurring hydrocarbons (all-Z)-henicosa-1,6,9,12,15,18-hexa
ene (1), (all-Z)-pentadeca-3,6,9,12-tetraen-1-yne (2, laurencenyne) and the
corresponding 3E-isomer 3 (trans-laurencenyne) have been accomplished.