steps with 27.5% overall yield from commercially available 1,2,3,5-tetra-O-acetyl-ribose and tetracyanoethylene. Key steps of the approach include: (1) I2 catalyzed acetonideformationfrom 1,2,3,5-tetra-O-acetylribose and acetone at large scale; (2) Vorbrüggen glycosylation using N4-benzoyl-5-cyano-6-bromo-7H-pyrrolo[2,3-d]pyrimidine as a nucleobase to avoid formation of N-3 isomer; (3) mild and scalable
In this paper, we report a total synthesis of a naturally occurring pyrrolo[2,3-d]pyrimidine nucleoside, mycalisine A. Our synthetic strategy uses D-xylose as the starting material and Vorbruggen glycosylation as the key step. Mycalisine A was synthesized in 11 steps with a 15% overall yield. (C) 2013 Qiang Xiao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.