In {TAIL ~ more detail}, {HEAD ~ a compound} having an S configuration selectively produces a compound having an S—R configuration, and a compound having an R configuration selectively produces a compound having an R—S configuration 
In
In { TAIL ~ more detail } , { HEAD ~ a compound } having an S configuration selectively produces a compound having an S — R configuration , and a compound having an R configuration selectively produces a compound having an R — S configuration
REL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH