str1 <- "L'école 'ici' nationale ' d'administration"
s1 <- gsub("(*UTF)(*UCP)\\s*'\\B|\\B'\\s*", "", str1, perl=TRUE)
s1
s2 <- gsub("(*UTF)(*UCP)\\b'\\b(*SKIP)(*F)|'", "", str1, perl=TRUE)
s2
gsub("(([^A-Za-z])'|'([^A-Za-z]))", "\\2 ", s2)