This document describes biochemical pathways for producing adipic acid, caprolactam, 6-aminohexanoic acid, hexamethylenediamine or 1,6-hexanediol by forming two terminal functional groups, comprised of carboxyl, amine or hydroxyl groups, in a C6 aliphatic backbone substrate. These pathways, metabolic engineering and cultivation strategies described herein rely on CoA-dependent elongation enzymes or analogues enzymes associated with the carbon storage pathways from polyhydroxyalkanoate accumulating bacteria.