Ethers are cracked to olefins using a gamma-alumina catalyst in the
presence of ammonia. The use of ammonia improves the selectivity to
linear alpha olefins in comparison to cracking reactions in the absence
of ammonia. The use of ammonia is convenient in comparison to known
processes which employ alumina which as been treated with an amine. A
preferred process produces octene-1 from 1-methoxyoctane.