or R1 is a 2 nitrobenzyloxycarbonyl of {TAIL ~ the formula} ##STR48## wherein R9 and R10 are {HEAD ~ H}, C1 C6 alkoxy, or R9 and R10 taken in combination are O CH2 O ; and 
or R1 is a 2 nitrobenzyloxycarbonyl of { TAIL ~ the formula } # # STR48 # # wherein R9 and R10 are { HEAD ~ H } , C1 C6 alkoxy , or R9 and R10 taken in combination are O CH2 O ; and
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH