Thexyldimethylsilyl TDS Ethers

The key intermediate 14, a stable tetrasubstituted tetrahydropyran derivative, was obtained from commercially available methyl o-glucopyranoside 12 via a three-step reaction sequence (Scheme 4). First the primary hydroxyl group was protected as thexyldimethylsilyl (TDS) ether, then the other OH groups were methylated under standard conditions to give 13. The latter glycoside was deoxy-genated at the anomeric position by treatment at room temperature with a Lewis acid (trimethylsilyl triflate) and a hydride donor (triethylsilane). This treatment also... 

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