Complex sentence: He was the first Puertorican and first alumni to be dean of the University of Puerto Rico School of Medicine from 1963 to 1967, later in 1967, he bacame the first rector of the newly formed University of Puerto Rico, Medical Sciences Campus.
Split into simpler sentences: He was the first Puerto Rican and first alumni to be dean of the University of Puerto Rico School of Medicine from 1963 to 1967. In 1967, he became the first rector of the newly formed University of Puerto Rico, Medical Sciences Campus.