Organic compounds

A compound of the formula,

• Ch.sub.3 --(ch.sub.2).sub.n --(CH .sup.cis CHCH.sub.2).sub.p --(CH.sub.2).sub.2 --Z I
• wherein
• n is an integer from 0 to 4,
• p is the integer 3 or 4, with the proviso that when p = 3, n must be 2 to 4, and when p = 4, n must be 0 or 1, and
• Z is one of the radicals of formula IIa, ##EQU12## wherein R.sub.1 and R.sub.2 are, independently, hydrogen or lower alkyl, of formula IIb, ##EQU13## wherein R.sub.2 is hydrogen or lower alkyl, or of formula IIc, ##EQU14## wherein R.sub.1 is hydrogen and lower alkyl, or a pharmaceutically acceptable salt thereof.