201804-22-0Relevant articles and documents
Arabinose-derived ketones as catalysts for asymmetric epoxidation of alkenes
Shing, Tony K. M.,Leung, Gulice Y. C.,Luk, To
, p. 7279 - 7289 (2007/10/03)
Readily available arabinose-derived ketones, containing a tunable butane-2,3-diacetal as the steric blocker, displayed increasing enantioselectivity (up to 90% ee) with the size of the acetal alkyl group in catalytic asymmetric epoxidation of trans-disubstituted and trisubstituted alkenes. The stereochemical communication between our ketone catalysts and the alkene substrates is mainly due to steric effect, and electronic effect involving π-π interaction between phenyl groups of substrate and of catalyst did not appear to be operative in our system.
Improved procedure for Julia-Colonna asymmetric epoxidation of α,β-unsaturated ketones: Total synthesis of diltiazem and Taxol side-chain
Adger, Brian M.,Barkley, James V.,Bergeron, Sophie,Cappi, Michael W.,Flowerdew, Benjamin E.,Jackson, Mark P.,McCague, Ray,Nugent, Thomas C.,Roberts, Stanley M.
, p. 3501 - 3507 (2007/10/03)
Poly-L-leucine catalyses the asymmetric epoxidation of enones 1-6 efficiently in a non-aqueous medium to provide the epoxy ketones 7-12 (70-91% yield; 80 to ≥95% ee). The strategy was used to make diltiazem 16 and the Taxol side chain 23 in single enantiomer form.