Efficient Chemical Synthesis of CMP-Neu5Ac and CMP-(Neu5Ac.alpha.2.fwdarw.8Neu5Ac)

Natural phosphoglycans containing glycosyl phosphate units: structural diversity and chemical synthesis

“…165 After coupling and oxidation, phosphotriester 69 was deprotected without purification by in situ addition of PPh 3 and (PPh 3 ) 4 Pd to provide CMP-Neu5Ac 70 in 25% yield (based on 67). The most successful procedure was published by Kajihara et al 166 Condensation of the sialic acid hemiacetal 63 and the tri-O,N-acetylcytidine 5 0 -phosphoramidite 71 in the presence of 1H-tetrazole, followed by oxidation (tert-BuOOH), gave the protected phosphotriester 72 (75%, as a diastereoisomeric mixture). Subsequent Pdeprotection (DBU) and treatment with NaOMe in aq methanol afforded CMP-Neu5Ac disodium salt 70 in 69% yield (52% based on 63).…”

“…Subsequent Pdeprotection (DBU) and treatment with NaOMe in aq methanol afforded CMP-Neu5Ac disodium salt 70 in 69% yield (52% based on 63). The same synthetic route was used effectively for the synthesis of the CMPNeu5Ac-dimer 73 166 and for the preparation of a set of bisubstrate-type sialyltransferase inhibitors 167 containing CMP-Neu5Ac as a fragment of the molecular structure.…”

Synthetic study of 3-fluorinated sialic acid derivatives

“…The conversion of 17 to a protected CMP-sialic acid derivative 19 was achieved according to an established procedure. 34 It was considered that the axial hydroxyl group in 17 could be directly used in phosphite formation with stereoretention under mild acidic conditions, as it has been reported that similar compounds could be obtained. 7 Thus, 17 was treated with 2-cyanoethyl 2 0 ,3 0 -O,N 4 -triacetylcytidine-5 0 -yl N,N-diisopropyl phosphoramidite 18 to give a phosphite, which was subsequently oxidized to a phosphate 19 using t-BuOOH.…”

Recent Progress in the Synthesis of Glycosyl Phosphate Derivatives

“…However, the application of this method to the synthesis of glycosyl phosphate derivatives has not been well explored (64)(65)(66)(67)(68)(69). Figure 16 shows an example of the synthesis of a phosphoglycan fragment by this method (64).…”