79762-35-9Relevant articles and documents
Synthesis of Curvulone B Using the 2-Chlorobenzyl Protecting Group
Bates, Roderick W.,Wang, Kongchen,Zhou, Guanying,Kang, Dave Zhihong
supporting information, p. 751 - 754 (2015/03/30)
A total synthesis of curvulone B has been completed using a Friedel-Crafts reaction and a highly cis-selective intramolecular oxa-Michael addition. The 2-chlorobenzyl protecting group was employed and found to have much greater Lewis acid stability compared to the simple benzyl group.
Inverting the regioselectivity of the berberine bridge enzyme by employing customized fluorine-containing substrates
Resch, Verena,Lechner, Horst,Schrittwieser, Joerg H.,Wallner, Silvia,Gruber, Karl,MacHeroux, Peter,Kroutil, Wolfgang
supporting information, p. 13173 - 13179 (2013/01/15)
Fluorine is commonly applied in pharmaceuticals to block the degradation of bioactive compounds at a specific site of the molecule. Blocking of the reaction center of the enzyme-catalyzed ring closure of 1,2,3,4- tetrahydrobenzylisoquinolines by a fluoro moiety allowed redirecting the berberine bridge enzyme (BBE)-catalyzed transformation of these compounds to give the formation of an alternative regioisomeric product namely 11-hydroxy-functionalized tetrahydroprotoberberines instead of the commonly formed 9-hydroxy-functionalized products. Alternative strategies to change the regioselectivity of the enzyme, such as protein engineering, were not applicable in this special case due to missing substrate-enzyme interactions. Medium engineering, as another possible strategy, had clear influence on the regioselectivity of the reaction pathway, but did not lead to perfect selectivity. Thus, only substrate tuning by introducing a fluoro moiety at one potential reactive carbon center switched the reaction to the formation of exclusively one regioisomer with perfect enantioselectivity. Custom-made substrates: Employing customized substrates with a fluoro atom at the normally preferred reaction site switched the regioselectivity of the berberine-bridged enzyme. With this strategy, it was possible to get access to (S)-11-hydroxy-functionalized berbines in an asymmetric fashion by using the wild-type enzyme (see scheme). Copyright
A diastereoselective formal synthesis of berkelic acid
Wenderski, Todd A.,Marsini, Maurice A.,Pettus, Thomas R. R.
supporting information; experimental part, p. 118 - 121 (2011/04/15)
A formal synthesis of berkelic acid is reported. The strategy employs the combination of a chiral exocyclic enol ether and an achiral isochromanone to afford the chroman spiroketal core via a base-triggered generation and cycloaddition of an o-quinone met
