Multigram Synthesis of Isobutyl-β-<i>C</i>-galactoside as a Substitute of Isopropylthiogalactoside for Exogenous Gene Induction in Mammalian Cells

Abstract

Herein we report that isobutyl-β-<i>C</i>-galactoside (IBCG) is also a promising inducer of gene expression in mammalian cells and report a new synthetic route to the compound that should make obtaining the multigram quantities of material required for animal studies more feasible. A convenient synthesis of IBCG, an inducer of genes controlled by the <i>lac</i> operon system in bacterial cells, was achieved in 5 steps from galactose in 81% overall yield without any chromatographic separation steps. An optimized microwave-assisted reaction at high concentration was key to making the <i>C-</i>glycosidic linkage. A Wittig reaction on a per<i>-O</i>-silylated rather than per-<i>O</i>-acetylated or -benzylated substrate proved most effective in installing the final carbon atom