3.8 C-Glycosylation
Toshio Nishikawa, Masaatsu Adachi, Minoru Isobe
Graduate School of Bioagricultural Sciences, Nagoya University,
464-8601 Nagoya, Japan
nisikawa@agr.nagoya-u.ac.jp, madachi@agr.nagoya-u.ac.jp,
isobem@agr.nagoya-u.ac.jp
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 756
2
Nucleophilic Addition to Electrophilic Carbohydrate Derivatives . . . . . . . . . . . 757
2.1
Lactol as an Electrophilic Carbohydrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 757
2.2
Lactone as an Electrophilic Carbohydrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 760
2.2.1 Reaction with Enolate and Related Anions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 760
2.2.2 Reaction with Wittig Reagents and Related Reagents . . . . . . . . . . . . . . . . . . . . . . . . . . 761
2.2.3 Reaction with Organometallic Reagents Followed by Reduction
of the Newly FormedHemiacetal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764
2.3
Glycosides (Halides, Oxygen, and others) as Electrophilic Carbohydrates . . . . . . . 766
2.3.1 Reaction with Grignard Reagents and Organoaluminum Reagents . . . . . . . . . . . . . . 767
2.3.2 Reaction with Organosilane and Organotin Reagents . . . . . . . . . . . . . . . . . . . . . . . . . . . 768
2.3.3 Aryl-C-Glycosylation with Aromatic Nucleophiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 771
2.4
Glycal as an Electrophilic Carbohydrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 776
2.5
Anhydrosugar as an Electrophilic Carbohydrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 780
3
Anomeric Radical Intermediate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785
3.1
Intermolecular Radical Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785
3.2
Intramolecular Radical Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789
4
Anomeric Anion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791
4.1
Lithium Anomeric Anion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791
4.2
Ramberg–Bäcklund Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 794
4.3
Samarium Anion Mediated Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 794
5
Sigmatropic Rearrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 798
6
Transition Metal-Catalyzed Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 802
Abstract
This chapter deals with C-glycosylation, a carbon–carbon bond-forming reaction at an
anomeric carbon of carbohydrate and its derivatives. Since synthesis of natural products
containing the C-glycosidic linkage was one of the major issues in organic synthesis in
the 1970s, extensive efforts have been devoted to developing stereoselective synthesis of
C-glycoside, which includes a variety of C–C bond formations by using anomeric cations
(oxocarbenium cations), anomeric radicals, and anomeric anions, as well as sigmatropic
In: Glycoscience. Fraser-Reid B, Tatsuta K, Thiem J (eds)
Chapter-DOI 10-1007/978-3-540-30429-6_17: © Springer-Verlag Berlin Heidelberg 2008