From cyclooctatetraene to chiral polyfunctionalized C8 building blocks—meso-persubstituted oxepanes and azepanes

Synthesis and glycosidase inhibitory activity of new hexa-substituted C8-glycomimetics

“…Thus, for example we had previously shown that the corresponding C7-voglibose mimic exhibited interesting activity towards amyloglucosidases from Aspergillus niger and Rhizopus mold (35 and 18 μM respectively, unpublished results). Furthermore, even if data concerning biological activity of C8-glycomimetics are seldom, the reported activities are often weak [ 24 - 30 ].…”

“…More recently, attention has been increasingly accorded to seven- and eight-membered ring systems [ 19 - 30 ] in order to study the effect of the enhanced flexibility and of the new spatial distribution displayed by these structures on their adaptability in the active site of the enzyme.…”

Advancements in the synthesis of polyoxygenated oxepanes and thiepanes for applications to natural products

“…82 Scheme 30 Synthesis of oxepanes via functionalized cyclooctatetraene. [79][80][81] Scheme 31 Synthetic route to thiepane via a ring-expansion strategy. 82…”

“…Armbruster and coworkers have demonstrated a strategy to synthesize meso persubstituted oxepanes using cyclooctatetraene via a modified skeletal rearrangement and ring contraction. 79 Synthesis of polyhydroxylated oxepane 181 or 182 started via cyclooctene 179 which containing two adjacent dimethyl ethers within a bis-epoxide system (Scheme 30). Intermediate 179 is obtained from a cyclooctatetraene, which was treated with trifluoroperacetic acid to yield a bis-1,5-epoxide system followed by a selective dihydroxylation using OsO 4 /NMO.…”

“…Modifying the nucleophile from water to primary amines allows access to N -substituted azepanes via a similar reaction sequence. 79…”