{HEAD ~ A process} 2 wherein said {TAIL ~ ring closure} is conducted using p toluenesulfonic acid or an ester or p toluenesulfonyl halide with a tertiary amine 
wherein
{ HEAD ~ A process } 2 wherein said { TAIL ~ ring closure } is conducted using p toluenesulfonic acid or an ester or p toluenesulfonyl halide with a tertiary amine
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH