methyl 2-[(tert-butoxycarbonyl)amino]hex-5-enoate

ethyl 2-tert-butoxycarbonylamino-5(E)-[6-N,N-dibenzoyl-5'-deoxy-2',3'-O-isopropylideneadenosin-5'-ylidene]pentanoate

ethyl (E)-2-(tert-butoxycarbonylamino)-5-(5'-deoxy-2',3'-O-isopropylideneuridin-5'-ylidene)pentanoate