The synthesis of alkyl-substituted biphenyl glucopyranosides

This account outlines the synthesis of three alkyl-substituted biphenyl glycosides 8a-8c (α and β). The aryl-aryl couplings of the 4-bromo- or 4-iodoanisoles (1a-1c) and 1-aIkyl-4-bromo- or 1- alkyl-4-iodobenzenes (2a-2c) were accomplished by utilizing an organometallic reagent to produce the biphenyl compounds 3a-3c. Demethylation of compounds 3a-3c was done via treatment with BBr₃ to yield analogs 4a-4c. All of the starting materials were not available for purchase, so 2c was made by diazotizing and halogenating 5. The glycosidation reactions to produce α, β mixtures of condensation products 7a-7c were catalyzed by SnCl₄. By varying the temperature and conditions of the reaction, both α and β products could be synthesized. Transesterification of products 7a-7c (α and β) with NaOMe in MeOH yielded the desired adducts 8a-8c (α and α).