Target molecule 1 poses several challenges, such as, 1. Synthesis of orthogonally protected rare sugar building blocks, 2. Stereoselective 1,2-cis glycosylation to introduce the isopropyl group on the rare AAT sugar, 3. Glycosylation of a GlcNAcA donor with the less reactive 4-OH GlcNAcA acceptor and, 4. Late stage amino acid coupling. An orthogonal Cbz group was employed to protect the 4C-NH2 group of AAT to exploit the long range anchimeric assistance for achieving 1,2-cis selectivity. The Cbz group can be selectively removed at a later stage to reveal the free NH2 group present in the native structure. The use of C2-azido group in AAT was necessary as a non-participating group, which can be converted into NHTCA group post-glycosylation. A direct glycosylation of N-acetyl glucuronate donors was preferred to avoid the complications arising due to late-stage oxidation. The TCA group was introduced to protect C2-NH2 in glucuronate building blocks for its advantageous neighboring group participation to achieve 1,2-trans selectivity in glycosylation, as well as its simultaneous For the synthesis of D-GlcNAcA donor 5, we started from known D-glucosamine 13 (Scheme 3) via TCA protection, per-O-acetylation, displacement of anomeric acetate with thiocresol, removal of acetate groups under Zemplén condition and regioselective benzylidene protection of 4,6 diol afford compound 8. The C3-OH group of compound 8 was benzylated to get compound 14. Subsequent benzylidene ring hydrolysis of 14 (85% yield) using p-TSA in MeOH: DCM (3:2), concomitant regioselective oxidation of primary hydroxyl group using TEMPO, BAIB in CH2Cl2/H2O and further benzyl ester formation with BnBr, NaHCO3 in DMF gave benzyl ester compound 15 in 60% over two steps. Conversion of thioglycoside donor 15 into trifluro imidate donor 5 was carried out by hydrolysis in the presence of NBS in THF:H2O (4:1) and its conversion into imidate using CF3C(NPh)Cl, K2CO3 in CH2Cl2 to furnish 2-NHTCA D-glucoronate donor 5.