wherein R1 is hydrogen, fluoro, chloro, or methyl; and R2 is C4 {TAIL ~ CS} branched {HEAD ~ alkyl} 
wherein R1 is hydrogen , fluoro , chloro , or methyl ; and R2 is C4 { TAIL ~ CS } branched { HEAD ~ alkyl }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD