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