There is disclosed a process for the production of dodecanedioic acid and 11-aminoundecanoic acid, comprising: (1) reacting castor oil with a primary or secondary amine to form a amide; (2) isomerizing the amide in the presence of a catalyst to form ketoamide; (3) reacting the ketoamide with hydroxylamine to form the oximeamide; (4) subjecting the oximeamide to Beckmann rearrangement to yield a mixture of two diamides; and (5) hydrolyzing the mixed diamides to produce dodecanedioic acid, 11-aminoundecanoic acid, hexylamine and heptanoic acid.