![]() This detachment is orthogonal to acidic and basic reaction conditions and therefore affords additional flexibility in the synthesis on solid support. Since their first description, photolabile linkers have received considerable attention during the past 25 years.3 It is widely recognized that photolysis offers a mild method of cleavage that takes place under neutral conditions. Introduction The rapidly growing field of combinatorial chemistry has renewed interest in the use of solid-phase organic synthesis techniques as a convenient means of assembling molecules.1,2 In addition to synthetic methods amenable to a solid-phase approach, the need for improved and novel linkers anchoring the molecules to the support has greatly expanded. The photolysis rates of our pivaloyl linker (2) were compared with the rates of a o-nitrobenzyl photolinker (1) and proved to be superior. The linker proved to be stable toward the treatment with acids and bases. Using this linker, we have demonstrated the solid-phase synthesis of test compounds by peptide synthesis, palladium-catalyzed cross coupling, and epoxidation. The pivaloyl linker (2) was found to cleave with high yields and purities the acids in various solvents (THF, CH2Cl2, dioxane, DMSO) by irradiation with light above 320 nm. Photocleavage is a two-step process, in which the immobilized acids are released by photolytic generation of a radical center and subsequent spontaneous β-C,O bond scission. The linker was prepared in six steps and anchored to the support via an amide bond. We have designed a new photolabile linker (2) based on 2-pivaloylglycerol for the solid-phase synthesis of acids. Johanns-Ring 19, CH-4056 Basel, Switzerland Received August 6, 1998 The Pivaloylglycol Anchor Group: A New Platform for a Photolabile Linker in Solid-Phase Synthesis Stefan Peukert and Bernd Giese* Department of Chemistry, University of Basel, St.
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