ABSTRACT
The first total synthesis of a major component of marine glycolipid vesparioside B ( Scheme 1 , 1, R1 = n-C22H45, R2 = n-C14H29) has been accomplished through a convergent [4 + 3] coupling strategy. Key steps included stereoselective installment of a set of challenging 1,2-cis-glycoside bonds. A 2-quinolinecarbonyl-assisted α-galactosylation and a novel ß-arabinosylation were developed, respectively, to synthesize the α-galactofuranosidic and the ß-arabinopyranosidic linkages. Furthermore, a 4,6-O-benzylidene-controlled α-galactopyranosylation reaction allowed the efficient connection of the left tetrasaccharide donor 2 with the right disaccharide lipid acceptor 3, hence leading to the total synthesis of 1.
Subject(s)
Glycosphingolipids/chemical synthesis , Porifera/chemistry , Animals , Glycosphingolipids/chemistry , Glycosylation , Hydrogen Bonding , Proton Magnetic Resonance SpectroscopyABSTRACT
The first total synthesis of batatin VI, an architecturally novel resin glycoside dimer, has been achieved via a convergent [5 + 3] glycosidic coupling approach. An improved protocol for the construction of the key 18-membered macrolactone core using a Keck macrolactonization method was introduced. However, the synthesized compound was not identical to the natural batatin VI.
Subject(s)
Macrolides/chemical synthesis , Oligosaccharides/chemical synthesis , Macrolides/chemistry , Molecular Structure , Oligosaccharides/chemistry , Resins, Plant/chemistry , StereoisomerismABSTRACT
The total synthesis of batatoside L (1), a resin glycoside possessing cytotoxicity against laryngeal carcinoma cells, has been completed in a highly convergent manner. The most crucial step in this total synthesis was the efficient construction of the 18-membered macrolactone framework through the Corey-Nicolaou macrolactonization approach.
