A new photocleavable linker in solid-phase chemistry for ether cleavage

[GRAPHICS] We have designed a new linker (1) for the solid-phase synthesis that cleaves ether bonds photolytically. The linker was prepared in nine steps and anchored to the support via an amide bond. Photocleavage is a two-step process in which the immobilized alcohols are released by photolytic generation of a radical that undergoes a spontaneous beta-bond scission. The pivaloyl linker (1) was found to cleave off alcohols in high yields and purities. Only traces of acid (pH similar to 5.5) are necessary for an efficient cleavage.