Stereocontrolled total synthesis of (5s,6r)-(7e,9e,11z,14z)-5-6-dihydroxy-7,9,11,14-icosatetraenoic, (5s,6s)-(7e,9e,11z,14z)-5-6-dihydroxy-7,9,11,14-icosatetraenoic, (5r,6r)-(7e,9e,11z,14z)-5-6-dihydroxy-7,9,11,14-icosatetraenoic, and (5r,6s)-(7e,9e,11z,14z)-5,6-dihydroxy-7,9,11,14-icosatetraenoic acid (5,6-dihete) methyl-esters