Synthesis of the C-glycosidic analog of adenophostin A, a potent IP3 receptor agonist, using a temporary silicon-tethered radical coupling reaction as the key step

Synthesis of the C-glycosidic analog (3) of adenophostin A, a very potent IP3 receptor agonist, was achieved using a temporary silicon-tethered reductive radical coupling reaction as the key step. Radical reaction of the silaketal substrate 6 with Bu3SnH/AIBN in benzene occurred stereoselectively, and subsequent desilylation gave the desired C-glycosidic disaccharide 7 with the (3α,1′α)-configuration as the major product. Compound 7 was converted into the target 3 via the introduction of an adenine base by a Vorbrüggen glycosylation reaction.