72748-98-2Relevant academic research and scientific papers
ENANTIOSELECTIVE SYNTHESIS OF PROTECTED α-HYDROXY ALDEHYDES AND KETONES VIA HYDROXYLATION OF METALATED CHIRAL HYDRAZONES
Enders, Dieter,Bhushan, Vidya
, p. 2437 - 2440 (2007/10/02)
α-Benzyloxy aldehydes and α-acetoxy ketones 4 of high enantiomeric purity are prepared in good overall yields via oxaziridine mediated hydroxylation of chiral hydrazone azaenolates.As auxiliaries novel proline derived hydrazine reagents 5 are used.
ASYMMETRIC MICHAEL ADDITIONS VIA SAMP-/RAMP-HYDRAZONES ANTI-DIASTEREO- AND ENANTIOSELECTIVE SYNTHESIS OF 3,4-DISUBSTITUTED 5-OXO-ALKANOATES
Enders, Dieter,Papadopoulos, Kyriakos,Rendenbach, Beatrice E.M.,Appel, Rolf,Knoch, Falk
, p. 3491 - 3494 (2007/10/02)
An efficient and highly anti-diastereo-(de=90-100percent) and enantioselective (ee=92-100percent) synthesis of 3,4-disubstituted 5-oxo-alkanoates 3 in good overall chemical yields is described.The procedure involves the asymmetric Michael addition of aldehydes or ketones to enoates via their lithiated SAMP-/RAMP-hydrazones.Both enantiomers are accessible at will.
ASYMMETRIC SYNTHESIS OF β-SUBSTITUTED δ-KETOESTERS VIA MICHAEL-ADDITIONS OF SAMP/RAMP-HYDRAZONES TO α,β-UNSATURATED ESTERS, VIRTUALLY COMPLETE 1.6-ASYMMETRIC INDUCTION
Enders, Dieter,Papadopoulos, Kyriakos
, p. 4967 - 4970 (2007/10/02)
A simple and efficient 3-step asymmetric synthesis of β-substituted δ-ketoesters 3 in 45-62percent overall chemical yield and >=96-ca.100percent ee is described.The key step is an asymmetric Michael-addition of lithiated methylketone-SAMP- or RAMP-hydrazones to α,β-unsaturated esters 2 with virtually complete 1.6-asymmetric induction.
