A dramatic effect is observed when acyclic N-(2-naphthamides) of medium-chain 1-amino-2-methylalkanes are partially ordered with the help of liposomes: the Cotton effect arising from pi-pi* transitions of the terminal naphthamide chromophor is enormously enhanced. This effect was exploited to assign the configuration of new polyketide peroxides such as 1 from the sponge Plakortis halichondroides.