Acetylation of the anomeric OH-group before TBDPS deprotection proved crucial to avoid formation of a furanose ring. Due to the acid and base sensitivity of compound 13, the TBDPS deprotection proved challenging. Classical conditions such as tetrabutylammonium fluoride or HF•pyridine did not yield satisfactory results. However, the tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) reagent, in presence of water allowed to carry out the TBDPS deprotection under mild conditions with a yield of 81%. The C(4)-OH group was then acylated to provide the 4-O-isobutyryl-, 4-O-cyclopropanoyl-, and 4-O-pivaloyl-noviose derivatives 15a-c. Finally, the anomeric acetate was converted to the thiol in a similar sequence as used before. However, due to the acid-sensitive nature of the acetonides 15a-c, bromotrimethyl silane (TMSBr) was used to form the glycosyl bromide. The freshly prepared, air and moisture sensitive glycosyl bromide was then subjected to substitution with thiourea and subsequent reduction using sodium metabisulfite. Thereby, the acetonide protected 4-O-acyl-1-thionoviose derivatives 17a-c were accessed as anomeric mixtures enriched in the targeted b-anomer.