find /directory1/directory2/ -maxdepth 1 -type f | sort | tail -n 5 | xargs md5sum
find
lists the files, no recursion, no directories, with full pathsort
list files alphabeticallytail
keep only the last 5 filesxargs
send the list as arguments to md5summd5sum
calculate the md5sum for each fileProbably can't handle spaces in file or directory names.