ABSTRACT
Methyl Ester ........................................................................... 611
12.3.2 Medermycin ........................................................................................................... 614
12.3.3 Urdamycinone B .................................................................................................... 615
12.3.4 Gilvocarcin M ........................................................................................................ 621
12.4 Others ................................................................................................................................. 621
12.4.1 Bidesmosidic Triterpene Saponin .......................................................................... 621
12.4.2 Digitoxin ................................................................................................................. 621
12.5 Concluding Remarks ......................................................................................................... 621
References ................................................................................................................................... 624
Many carbohydrate-containing complex natural compounds are found in nature as important
biological substances [1]. A large number of recent biological studies on these glycosubstances,
which possess mono-and oligosaccharides, such as proteoglycans, glycoproteins, glycolipid and
antibiotics at the molecular level have shed light on the biological significance of their carbohydrate
parts (glycons) in molecular recognition for the transmission of biological information. Therefore, it
is now recognized that carbohydrates are at the heart of a multitude of biological events. With the
stimulant biological background, the efficient synthesis of not only the carbohydrate itself but also
carbohydrate-containing complex natural compounds is becoming more and more important in the
field of organic chemistry and chemical biology [2]. For the efficient total or partial synthesis of
mono-and oligosaccharide-containing complex natural products, there are several issues to
overcome. The first one is the moment of glycosidation [3], the carbohydrate attachment, within the
planned sequence so as to optimize efficiency. The second issue relates to the choice of the
glycosidation method to be used with regard to the yield and the stereoselectivity. The third issue is
associated with the choice of appropriate protecting groups [4]. This chapter focuses on highlights of
the carbohydrate chemistry leading to the successful total synthesis of some representative natural
products possessing both mono-and oligosaccharide side chains and complex noncarbohydrate
components, except for glycoproteins and glycolipids. In this survey of the current advances in this
area, the carbohydrate-containing complex natural compounds are arbitrarily classified into three
groups: (1) O-glycoside antibiotics, (2) C-glycoside antibiotics and (3) others.
