The highly selective delta (δ) opioid receptor agonist SNC 80 [(+)-4-[(α R)-α-((2 S, 5 R)-4- allyl-2, 5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N, N-diethylbenzamide,(+)-21] and novel optically pure derivatives were synthesized from the enantiomers of 1-allyl-trans-2, 5- dimethylpiperazine (2). The piperazine (±)-2 was synthesized, and its enantiomers were obtained on a multigram scale in> 99% optical purity by optical resolution of the racemate ...