Stereoselective Synthesis of α(2,9) Di- to Tetrasialic Acids, Using a 5,4-N,O-Carbonyl Protected Thiosialoside

• Published in: Journal of organic chemistry Vol. 74; no. 11; pp. 4383 - 4386
• Main Authors: Tanaka, Hiroshi, Nishiura, Yuji, Takahashi, Takashi
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 05.06.2009; Amer Chemical Soc
• Subjects: Carbohydrates with 4, 5, 6, ... C atoms, dissacharides and oligosaccharides; Carbohydrates. Nucleosides and nucleotides; Chemistry; Chemistry, Organic; Exact sciences and technology; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; Sialic Acids - chemical synthesis; Stereoisomerism; Thiosugars - chemistry; THIOGLYCOSIDE; DONOR; SIALOSIDES; SIALIC-ACID; GLYCOSYLATION; GLYCOPROTEIN; O-SIALYLATION; N-ACETYLNEURAMINIC ACID; ACETYL-NEURAMINIC ACID; GLYCOSIDE SYNTHESIS; Protecting group; Sialic acid; Deprotection; Oside; Selectivity; Ketone; Stereoselectivity; Ketoaldonic acid; Cyclic compound; Tetramer; Acetonitrile; Thioglycoside; Chemical synthesis; Protection; Solvent
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo900176e

An efficient stereoselective synthesis of α(2,9) tetra- to disialic acids 1−3, using the 5,4-N,O-carbonyl protected thiosialoside 4, is described. The cyclic protecting group was effective for α-sialylation without the need for acetonitrile as the solvent. The donor 4 enabled the formation of a tetramer in excellent yield and selectivity. Deprotection of the cyclic protecting groups of the protected di- to tetrasialica acids proceeded smoothly to give the fully deprotected α(2,9) tetra- to disialic acids 1−3.