Regioselective 6-detrimethylsilylation of per-O-TMS-protected carbohydrates in the presence of ammonium acetate

An improved method for the large scale preparation of α,α′-trehalose-6-phosphate

“…One important feature of the new synthetic route involves the use of NH 4 OAc for selective O-6 monodesilylation of readily prepared 2,3,4,6,2 0 ,3 0 ,4 0 ,6 0 -octa-(O-trimethylsilyl)-a,a 0 -trehalose. The idea of using this selective NH4OAc came from the work of Cui et al, 11 which demonstrated that, in contrast to others like K 2 CO 3 , this reagent promotes reliably clean and selective removal of TMS groups at the 6-position of per-Otrimethylsilylated carbohydrates.…”

Synthesis and Structural Characterization of Three Unique Helicobacter pylori α‐Cholesteryl Phosphatidyl Glucosides

“…Regioselective phosphatidylation at the C6 position was initiated with the synthesis of compound 4 , which was achieved using our glycosyl iodide one‐pot glycosylation protocol starting from per‐ O ‐TMS glucose 10. In this manner, we could generate per‐ O ‐silylated αCG ( 4 ) and then regioselectively desilylate the primary ether at C6 using ammonium acetate in dichloromethane and methanol to afford the free alcohol ( 16 , Scheme ) 13. The synthetic route to αCPG through compound 16 avoids the formation of a phosphite acetal between the hydroxy groups at C4 and C6 of unprotected αCG( 1 ) and any acyl migration event that could occur 8.…”

Synthesis of carbohydrate building blocksviaregioselective uniform protection/deprotection strategies

“…116 Cui et al developed a method to selectively remove a primary trimethylsilyl (TMS) group of per- O -TMS protected carbohydrates using ammonium acetate (NH 4 OAc). 117 On the treatment of the per-O-TMS protected glucoside 78 with 2 equiv. of NH 4 OAc the corresponding 6-OH product 79 was obtained in 91% yield (Scheme 14).…”