Bicyclo[2.2.2]octane-derived chiral ligands—synthesis and application of BODOLs in the asymmetric reduction of acetophenone with catecholborane

Proteasome-inhibitory and cytotoxic constituents of Garcinia lateriflora: absolute configuration of caged xanthones

“…In turn, the A-ring occurred in a boat conformation connected with the B ring, with a C-26 and C-27 bridge above or below the plane to form a bicyclic [2.2.2]-octane unit (Figure 5). 34,35 NOESY correlations were observed between H-7 and H-8, H-8a, H-21, H-29, and H-25, H-8 and H-8a, H-8a and H-22, and H-25, H-27 and H-30 and H-26a, H-25 and H-29, H-30, and H-22 (Figure 5). Based on these NOESY correlations and 7 S configuration of 3 , a S configuration for both C-10a and C-27 and a R configuration for C-5 and C-8a were assigned for 3 .…”

Totalsynthese von (+)‐Crotogoudin

“…Interessanterweise funktionierte diese Reaktion am entsprechenden TBS‐geschützten Hydroxyketon nicht 16. Wenn hingegen der freie Alkohol 5 mit 2 Äquivalenten des Grignard‐Reagens umgesetzt wurde, entstand der gewünschte tertiäre Alkohol mit hervorragender Diasteroselektivität, jedoch nur in geringer Ausbeute 17. Grund ist die konkurrierende Enolisierung des Ketons, welche zur Rückbildung von Ausgangsmaterial führte.…”

Asymmetric baker’s yeast reductions of bridgehead-substituted bicyclo[2.2.2]octane-2,6-dione derivatives followed by conversion into catalytically active BODOLs for the diethylzinc addition to benzaldehyde

“…16,17,[20][21][22] For the asymmetric diethylzinc addition, most satisfactory results were obtained with BODOLs bearing an o-anisyl substituent at the 2-position (89%, 92% ee). Thus, we decided to transform optically active hydroxy ketones (À)-19 and (À)-22 into 2-o-anisyl BODOLs and investigate their catalytic capacity in the asymmetric diethylzinc addition (Scheme 6).…”

“…[16][17][18][19][20][21][22][23][24][25] New applications for bicyclo [2.2.2]octanes are presented continuously. Recently, Baran et al reported the synthesis of polyhydroxylated bicyclic systems, which exhibited enzyme-specific inhibition against a-glycosidase.…”