Membrane receptor probes: solid-phase synthesis of biotin-Asp-PEG-arvanil derivatives

[structure: see text] A modular, flexible solid-phase synthetic route for the preparation of biotinylated cross-linking probes of membrane receptors is described. The route utilizes an orthogonal protection strategy employing a Pd[0] cleavable allyl linker attached to the probe via an aspartate residue. The versatility of the method is illustrated through the synthesis of a number of arvanil-derived cannabinoid receptor ligands displaying either a photoaffinity or a chemical cross-linking group.