A novel synthesis of 1,2-cis-disaccharides

Development of chemical and chemo-enzymatic glycosylations

“…In 1980, Schmidt et al improved the “imidate method” developed by Sinaÿ et al in 1977 6) to the “trichloroacetimidate method” where an O–C=N moiety could be constructed using the nucleophilicity of hemiacetals and activated by a protonic acid or BF 3 -OEt 2 (Fig. 4, lower-side).…”

General Aspects of the Glycosidic Bond Formation

“…During the 1970s to early 1980s, a few new classes of glycosyl donors were developed. The following compounds are only the most representative examples of the first wave of the leaving-group development: thioglycosides by Ferrier et al [17], Nicolaou et al [18], Garegg et al [19] and others [20]; cyanoethylidene and orthoester derivatives by Kochetkov and coworkers [21,22]; O-imidates by Sinay and coworkers [23] and Schmidt and Michel [24]; thioimidates including S-benzothiazolyl derivatives by Mukaiyama et al [25]; thiopyridyl derivatives by Hanessian et al [26] and Woodward et al [27] and glycosyl fluorides by Mukaiyama et al [28] (Figure 1.2). Many glycosyl donors introduced during that period gave rise to excellent complimentary glycosylation methodologies.…”

Synthesis of Hetaryl Glycosides and Their Glycosyl Donor Properties

“…However, by judicious selection of the heterocyclic system, i.e. those incorporating electron-with-Under trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalysis in diethyl ether solution, these O-benzyl protected drawing substituents or ring constituents, it should be possible to achieve high glycosyl donor properties under con-glycosyl donors afforded the known disaccharides 18aα, β [27] and 19aα, β [28] in good to high yields, mainly or even ditions of mild acid catalysis.…”

“…[30] (153 mg), flash chromatography ture T given below, the reaction mixture was allowed to warm to ( [27] [28] : Under argon, the glycosyl donor (0. 26 mmol) [25] or 19 [26] (0.…”