96925-01-8Relevant articles and documents
Additions of Organomagnesium Halides to α-Alkoxy Ketones: Revision of the Chelation-Control Model
Read, Jacquelyne A.,Yang, Yingying,Woerpel
, p. 3346 - 3349 (2017/07/13)
The chelation-control model explains the high diastereoselectivity obtained in additions of organometallic nucleophiles to α-alkoxy ketones but fails for reactions of allylmagnesium halides. Low diastereoselectivity in ethereal solvents results from no chelation-induced rate acceleration. Additions of allylmagnesium bromide to carbonyl compounds are diastereoselective using CH2Cl2 as the solvent even though rate acceleration is still absent. Stereoselectivity likely arises from the predominance of the chelated form in solution. Therefore, a revised chelation-control model is proposed.
Access to functionalized steroid side chains via modified Julia olefination
Izgu, Enver Cagri,Burns, Aaron C.,Hoye, Thomas R.
, p. 703 - 705 (2011/04/26)
Various functionalized steroidal side chains were conveniently accessed by a modified Julia olefination strategy using a common sulfone donor and an appropriate α-branched aldehyde acceptor. For the coupling of these hindered classes of reaction partners (and in contrast to typically observed trends), the benzothiazolyl(BT)-sulfone anion gave superior outcomes compared to the phenyltetrazolyl(PT)-sulfone anion.
Stereoselective Bromination of Dehydroamino Acids with Controllable Retention or Inversion of Olefin Configuration
Coleman, Robert S.
, p. 4452 - 4461 (2007/10/02)
Dehydroamino acids react with brominating reagents to produce syn-α-bromo imines as the major products, which undergo tautomerization to mixtures of the diastereomeric (E)- and (Z)-β-bromo-α,β-dehydroamino acids upon treatment with base.Herein, we examine
