The compound 6, wherein the stereochemistry of the carbon to which {HEAD ~ R2} and R3 are attached is of {TAIL ~ the S onfiguration} 
The compound 6 , wherein the stereochemistry of the carbon to which { HEAD ~ R2 } and R3 are attached is of { TAIL ~ the S onfiguration }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL