Levene; Marker, Journal of Biological Chemistry, 1935, vol. 111, p. 306
作者:Levene、Marker
DOI:——
日期:——
Stereoselective synthesis of α-methyl and α-alkyl ketones from esters and alkenes<i>via</i>cyclopropanol intermediates
作者:Maryia V. Barysevich、Volha V. Kazlova、Aliaksandr G. Kukel、Aliaksandra I. Liubina、Alaksiej L. Hurski、Vladimir N. Zhabinskii、Vladimir A. Khripach
DOI:10.1039/c8cc00888d
日期:——
undergo Kulinkovich hydroxycyclopropanation with good diastereoselectivity. For the isomerization of the resulting cyclopropanols to diastereomerically enriched α-methyl ketones, a new mild regioselective method has been developed. A sequence of stereoselective cyclopropanation and cyclopropanol ring opening was successfully employed for the construction of the C20 stereocenter in steroids.
A catalytic and iterative route to β-substituted esters via highly enantioselective conjugate addition of dimethylzinc to unsaturated malonates
作者:Julia Schuppan、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1039/b315871c
日期:——
Using the chiral phosphoramidite ligand (S,R,R)-L1 in the conjugateaddition of dimethylzinc to acyclic unsaturated malonates, enantioselectivities of up to 98% have been obtained for the first time. An iterative and stereodivergent route to 3,5-dimethyl esters that takes advantage of this asymmetric catalysis has been developed.