Skip to main content
. Author manuscript; available in PMC: 2020 May 20.
Published in final edited form as: Angew Chem Int Ed Engl. 2019 Apr 9;58(21):6957–6961. doi: 10.1002/anie.201901346

Scheme 2.

Scheme 2.

Synthesis of octasaccharide 40. [a] 5 – 15 mol% of 4, IBO (2 equiv.), MTBE (2 M), 50 oC, 24 h, 34: 89%, α:β > 20:1; 37: 86%, α:β > 20:1; 40: 77%, α:β > 20:1. [b] NaOMe, MeOH, CH2Cl2, 25 oC, 35: 99%, 38: 70%. [c] PTSA, Ac2O, 70 oC, 2 h (glycosyl acetates: 36S: 61%, 39S: 51%, see SI); then HBr/AcOH, CH2Cl2, 0 oC, 15 min, and 36 and 39 were used in the next step without further purification.