Designing an effective approach for obtaining methylenecarboxylate analogues of adenophostin A. Preliminary results

Preliminary results for the synthesis of two new adenophostin analogues incorporating 3″- and 4″-methylenecarboxylate surrogate groups are presented. The synthesis involves the preparation of 3″- and 4″-methylenecarboxylate glucose derivatives by a radical allylation-oxidative cleavage approach, their conversion into thioglycoside precursors, and stereoselective glycosylation of a suitable adenosine derivative. The glycosylations proceeded with excellent stereoselectivity, only the α product was detected, and in good yields.