{HEAD ~ Scheme} 3 illustrates {TAIL ~ a method} of synthesizing the R and S enantiomers of the starting materials of the formula VII wherein X is sulfur 
illustrates
{ HEAD ~ Scheme } 3 illustrates { TAIL ~ a method } of synthesizing the R and S enantiomers of the starting materials of the formula VII wherein X is sulfur
HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH