Synthesis of substituted 2,7-dioxabicyclo[4.1.0]heptanes: 1,2-anhydro-3,4,6-tri-O-benzyl- and 1,2-anhydro-3,4,6-tri-O-(p-bromobenzyl)-α-d-galactopyranose

A Method of Orthogonal Oligosaccharide Synthesis Leading to a Combinatorial Library Based on Stationary Solid‐Phase Reaction

“…Analysis by quadrupole ion‐trap mass spectrometry (QITMS) revealed that disaccharide 12 (where R in Table 1 is A 2 ) ( m / z =801.3) was formed with excellent efficiency (Figure 2 a). Furthermore, glycosylation of 10 with compound 15 (2‐OH form)34 was also carried out to yield resin‐bound 16 . An extremely high yield was shown again by QITMS analysis (Figure 2 b)…”

Synthesis of Fucosyl Saccharides under Neutral Conditions in Solutions of Lithium Perchlorate in Dichloromethane

“…The respective acceptors employed in this study were built up by means of 1,2-anhydro carbohydrates, that is, the anhydro glucopyranose 5 [7] and the anhydro galactopyranose 10, [8] which were recently employed by Danishefsky et al [9] in several oligosaccharide syntheses. Since glycosylations using these epoxides, in general, are promoted by Lewis acids, we reasoned that these anhydro pyranoses might also be activated in solutions of LiClO 4 in organic media.…”

“…The carbohydrates 5, [7] 6, [21] 10, [8] 17, [14] 18, [22] 19, and 20 [15] were prepared as described in the literature.…”

Direct epoxidation of d-glucal and d-galactal derivatives with in situ generated DMDO

“…The 1 H NMR data were identical to those reported previously. 13 To a vigorously stirred, cooled (ice bath) biphasic solution of tri-O-acetyl-glucal 7 (3.00 g, 11.02 mmol) in CH 2 Cl 2 (50 mL), acetone (5 mL) and satd aq NaHCO 3 (100 mL), a solution of Oxone (13.6 g, 22.12 mmol) in H 2 O (60 mL) was added dropwise over 20 min. The mixture was vigorously stirred at 0°C for 30 min and then at rt for an additional 6 h. The organic phase was separated and the aqueous phase extracted with CH 2 Cl 2 (3 · 30 mL).…”