preferred_name: 1-(9Z,12Z-octadecadienoyl)-2-acyl-sn-glycero-3-phosphocholine + 2 Fe(II)-[cytochrome b5] + O2 + 2 H(+) = 1-(9Z,12Z,15Z-octadecatrienoyl)-2-acyl-sn-glycero-3-phosphocholine + 2 Fe(III)-[cytochrome b5] + 2 H2O