Development of a Flexible and Robust Synthesis of Tetrahydrofuro[3,4- b]furan Nucleoside Analogues

J Org Chem. 2021 Apr 2;86(7):5142-5151. doi: 10.1021/acs.joc.0c02969. Epub 2021 Mar 23.

Abstract

In the context of a PRMT5 inhibitor program, we describe our efforts to develop a flexible and robust strategy to access tetrahydrofuro[3,4-b]furan nucleoside analogues. Ultimately, it was found that a Wolfe type carboetherification from an alkenol derived from d-glucofuranose diacetonide was capable of furnishing the B-ring and installing the desired heteroaryl group in a single step. Using this approach, key intermediate 1.3-A was delivered on a gram scale in a 62% yield and 9.1:1 dr in favor of the desired S-isomer. After deprotection of 1.3-A, a late-stage glycosylation was performed under Mitsunobu conditions to install the pyrrolopyrimidine base. This provided serviceable yields of nucleoside analogues in the range of 31-48% yield. Compound 1.1-C was profiled in biochemical and cellular assays and was demonstrated to be a potent and cellularly active PRMT5 inhibitor, with a PRMT5-MEP50 biochemical IC50 of 0.8 nM, a MCF-7 target engagement EC50 of 3 nM, and a Z138 cell proliferation EC50 of 15 nM. This work sets the stage for the development of new inhibitors of PRMT5 and novel nucleoside chemical matter for alternate drug discovery programs.

MeSH terms

  • Cell Proliferation
  • Enzyme Inhibitors
  • Furans
  • Nucleosides*
  • Protein-Arginine N-Methyltransferases*

Substances

  • Enzyme Inhibitors
  • Furans
  • Nucleosides
  • Protein-Arginine N-Methyltransferases