Page 391 - Cascade_Biocatalysis_Integrating_Stereoselective_and_Environmentally_Friendly_Reactions

17.2 A Generic Strategy for the Synthesis of Sialoconjugate Libraries 367

OH OH
HO OH OH OH
O CO H O CO H O H
AcNH 2 AcNH 2 AcNH CO 2
HO OH 1 HO OH 1a HO OH 1b
OH OH OH
OH HO OH + H N OH
3
O CO H O CO H O CO H
AcNH 2 AcNH 2 AcNH 2
HO OH HO HO
1c 1d OH 1e
OH OH OH
AcO OH N 3 OH HO OH
AcNH O CO 2 H AcNH O CO 2 H AcNH O CO H
2
HO OH 1f HO OH 1g N 3 OH 1h
OH OMe OH
MeO OH HO OH F OH
O CO H O CO H O
AcNH 2 AcNH 2 AcNH CO 2 H
HO OH HO OH HO OH
1i 1j 1k
(a)
OH OH OH
HO OH OH HO OH
O H O O CO H
HO CO 2 HO CO H 2
2
HO OH HO OH HO OH
3 3a 3b
OH
OH OH
OH HO OH HO OH
O H O H O H
HO CO 2 HO CO 2 CO 2
HO OH HO OH HO OH
3c 3d 3e
OH OH OH
AcO OH HO OH AcO OH
O CO 2 H O CO 2 H O CO 2 H
HO AcO AcO
HO OH HO OH HO OH
3f 3g 3h
OH OMe OH
MeO OH HO OH HO OH
O CO H O H O H
HO 2 HO CO 2 HO CO 2
HO OH 3i HO OH 3j MeO OH 3k
OH
HO OH
O CO 2 H
MeO
(b) HO OH 3l
Scheme 17.3 Structurally modified sialic acids used as synthetic probes for the Leloir-path
sialyltransfer enzymes, and toward the preparation of natural sialoconjugates and non-
natural neo-sialoconjugate. (a) Structural variations of Neu5Ac. (b) KDN.