Compounds of Formula I, their preparation and synthetic intermediates, and their use in the synthesis of prodrugs: ##STR00001## wherein: V and L are trans relative to one another; V is selected from group consisting of carbocyclic aryl, substituted carbocyclic aryl, heteroaryl, and substituted heteroaryl; and L is a leaving group selected from the group consisting of halogen, alkyl sulfonate, aryloxy optionally substituted with 1 2 substituents, N-containing heteroaryl, and N-hydroxy-nitrogen containing heteroaryl; and salts thereof.