15,15-Ketals of natural prostaglandins and prostaglandin analogues. Synthesis and biological activities.

ABSTRACT

The synthesis is described of new 15,15-ethylene ketals of natural prostaglandins and prostaglandin analogues. Especially the crystalline trisamine salt of the 15,15-ethylene ketal of 15-dehydro-16-phenoxy-17,18,19,20-tetranorprostaglandin F2alpha is a very active inducer of luteolysis in laboratory animals and cattle.