Stereocontrolled synthesis of anthracene β-C-ribosides: fluorescent probes for photophysical studies of DNA

Selenium as a Key Element for Highly Ordered Aromatic Self‐Assembled Monolayers

“…Bashir, 1) D. Käfer, 1) J. Müller, 2) Ch. Wöll, 1) A. Terfort, 2) and G. Witte Chemical synthesis of selenoacetic acid Se-anthracen-2-yl ester.…”

“…Wöll, 1) A. Terfort, 2) and G. Witte Chemical synthesis of selenoacetic acid Se-anthracen-2-yl ester. 2-Bromoanthracene (1.13 g, 4.39 mmol) [1] was dissolved in THF (80 ml), cooled down to -78°C and tert.-butyllithium (5.9 ml, 8.9…”

“…2-Bromoanthracene (1.13 g, 4.39 mmol) [1] was dissolved in THF (80 ml), cooled down to -78°C and tert.-butyllithium (5.9 ml, 8.9mmol) was added to this dropwise. After stirring during warming up to 0°C and cooling back to -78°C, black selenium powder (0.35 g, 4.4 mmol) was added.…”

“…2-Bromoanthracene (1.13 g, 4.39 mmol) [1] was dissolved in THF (80 ml), cooled down to -78°C and tert.-butyllithium (5.9 ml, 8.9…”

The Synthetic Versatility of Acyloxyborohydrides

“…The enormous power of the method is revealed in the list of natural product syntheses (or approaches thereto) that have employed -hydroxy-directed reduction of ketones using NaBH(OAc) 3 (or Me 4 NBH(OAc) 3 (in no special order): cyclophellitol, 158 sanglifehrin A, 159 aurisides A and B aglycon, 160 Several groups have reported the -hydroxyl-directed reduction of various ketonucleosides. [188][189][190][191][192][193][194][195][196] Simple systems also undergo this stereoselective reduction (e.g., 65), 197 and the method has been applied to the synthesis of polypropionates. 198 Although a chairlike transition state (Scheme 10) does not operate in the acylborohydride reduction of R-hydroxy ketones, these substrates nevertheless can be reduced via intramolecular hydride delivery leading to syntheses of allopumiliotoxin A, 199 the bruceantin quassinoids, 200 and the rocaglamides 201 (Scheme 12).…”