An unusual solvent effect on the regiochemical outcome (N-9 versus N-7) of guanine glycosylation using Robins' reagent (2-N-acetyl-6-O-diphenylcarbamoylguanine)
AWH Cheung, A Sidduri, LM Garofalo, RA Goodnow
文献索引：Cheung, Adrian Wai-Hing; Sidduri, Achyutharao; Garofalo, Lisa M.; Goodnow Jr., Robert A. Tetrahedron Letters, 2000 , vol. 41, # 18 p. 3303 - 3307
An unexpectedly low N-9/N-7 regioselectivity was obtained when Robins' reagent (2-N- acetyl-6-O-diphenylcarbamoylguanine) was coupled with a d-glucosamine derivative under trimethylsilyl trifluoromethanesulfonate activation. An unprecedented solvent effect (toluene versus dichloroethane) on the N-9/N-7 ratio was also observed in the same study. The use of 2-N-acetyl-6-O-benzylguanine to successfully overcome the above regioselectivity ...
