1569-45-5Relevant articles and documents
Stereoselective allylation of ketones: Explanation for the unusual inversion of the induced stereochemistry in the auxiliary-mediated crotylation and pentenylation of butanone by DFT calculations
Tietze, Lutz F.,Kinzel, Tom,Schmatz, Stefan
, p. 1706 - 1712 (2009)
Auxiliary-mediated domino crotylations and pentenylations of butanone yield homoallylic ethers with two newly formed stereogenic centers. With our norpseudoephedrine-derived auxiliary, we observed the formation of anti isomers exclusively, and the nature
Diastereoselectivity in the Addition of Crotylmagnesium Bromide to Unsymmetrical Ketones
Sjoeholm, Rainer E.
, p. 82 - 89 (2007/10/02)
Reactions of the Grignard reagent prepared from 1-bromo-2-butene (crotylmagnesium bromide, CH3CH=CHCH2MgBr) with 19 unsymmetrical ketones (R'RC=O;R'R; R=Me and R'=Et, i-Pr, c-Hex or t-Bu; R=Me, Et, i-Pr, c-Hex or t-Bu and R'=2-Fur, 2-Th or Ph) have been performed in order to study the diastereoselectivity of the reaction.All ketones gave two diastereomers of tertiary homoallyl alcohols formed by addition of an α-methylallyl group.With dialkyl ketones the major isomer had the anti configuration.With alkyl aryl(heteroaryl) ketones the syn isomer predominated.Thediastereoselectivites were quite low, except with t-Bu ketones which gave a maximum de of 84.Possible transition states are discussed and a mechanism is proposed based on our observations.
