Occurs in oil of orange. Prepn by reduction of ethyl Δ1-nonylenate: Harding, Weizmann, J. Chem. Soc. 97, 304 (1910); by reduction of pelargonic aldehyde: Tomecko, Adams, J. Am. Chem. Soc. 49, 529 (1927); by oxo process: Russum, Hengstebeck, US 2638487 (1953 to Standard Oil of Indiana); by reductive cleavage of oleic acid ozonide: Sousa, Bluhm, J. Org. Chem. 25, 108 (1960); from diborane and propylene trimer: Marshall, Smith, GB 879242 (1961 to I.C.I.).