A process 2, wherein {HEAD ~ R1}, R2 and R3 are {TAIL ~ hydrogen} and R4 is a lower alkyl group 
A process 2 , wherein { HEAD ~ R1 } , R2 and R3 are { TAIL ~ hydrogen } and R4 is a lower alkyl group
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH