Selective substitution of a sulfur atom by carbon in a highly potent 13-mem
bered cyclic disulfide was accomplished by intramolecular displacement of a
bromide. The potency of the resulting thioethers in the VCAM/VLA-4 assay w
as dependant on rin size and the position of the sulfur atom. (C) 2000 Else
vier Science Ltd. All rights reserved.