Abstract: Novel compounds are disclosed of the classes: ##STR1## wherein the subscript n is an integer from 3-5, inclusive, R.sub.1 is hydrogen or R.sub.2 ; R.sub.2 and R.sub.3 consist essentially of C.sub.1 -C.sub.6 alkyl and R.sub.2 may be the same as or different from R.sub.3, and wherein Aryl consists essentially of phenyl and phenyl substituted with halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, and trifluoromethyl;(b) derivatives of furan having the formula ##STR2## wherein R.sub.4 consists essentially of hydrogen and C.sub.1 -C.sub.6 alkyl, and W is either carbonyl or carbinol; and(c) cyclopentenonyl compounds having the formulas ##STR3## wherein R.sub.5 consists essentially of hydrogen and C.sub.1 -C.sub.6 alkyl, P.sub.1 is hydrogen or a protective group, Y is either ##STR4## A new process is disclosed for preparing 1-(methyl)-16,16-(dimethyl)-11-alpha-15-alpha-dihydroxy-9-oxo-2,13,trans, trans-prostadienoate, and congeners thereof, including racemic mixtures.