(11R,12R)-(5Z,8E)- and -(5Z,8Z)-11,12-Epoxy-13-hydroxy-5,8-tridecadien
oic acids were synthesized from 3-butyn-1-ol and were shown to cyclize
to the delta-lactone of (12S)-(7E, 10E)-5,12,13-trihydroxy-7,10-tride
cadienoic acid with stannic chloride in nitromethane.