The present invention provides compounds for treating or preventing an HIV infection, or treating AIDS or ARC comprising administering a compound according to formula I where Ar, R
1
-R
5
, R
11c
and X
1
are as defined herein.
The present invention provides compositions for treating an HIV infection comprising administering a compound according to formula I where Ar, R
1
-R
5
, R
11c
and X
1
are as defined herein with at least one carrier, excipient or diluent.