104758-28-3

Upstream product

• 77877-19-1 N-isopropyl oxazolidinone 
• 100-52-7 benzaldehyde 
• 186355-83-9 (2'RS,4S)-3-(2'-bromopropanoyl)-4-(1-methylethyl)-oxazolidin-2-one 
• 17016-83-0 (4S)-4-isopropyl-1,3-oxazolidin-2-one 

Downstream Products

• 76549-03-6 methyl (2S,3S)-3-hydroxy-2-methyl-3-phenylpropanoate 
• 76549-05-8 methyl (2R,3R)-3-hydroxy-2-methyl-3-phenylpropanoate 
• 36041-80-2 (2R,3S)-methyl 3-hydroxy-2-methyl-3-phenylpropanoate 

Relevant academic research and scientific papers

(4S)-3-[(2R,3S)-3-Hydroxy-2-methyl-3-phenylpropionyl]-4-isopropyl- oxazolidin-2-one

The molecule of the title compound, C16H21NO 4, is chiral and has three asymmetric centres. The absolute configuration was not determined via diffraction measurements on the crystal, but was established from the known abso

ASYMMETRIC ALDOL REACTIONS. MECHANISM OF SOLVENT EFFECT ON STEREOSELECTIVITY IS SPECIFIC, STOICHIOMETRIC BINDING OF TETRAHYDROFURAN TO A CHIRAL TITANIUM ENOLATE

Solvent plays an important role in aldol reactions of an acyloxazolidinone-derived titanium enolate.Diethyl ether produces nearly fivefold higher diastereofacial selectivity than THF.We now show that this strong solvent effect arises from stoichiometric binding, most probably to the titanium, of THF in the transition structure, whereas ether is not bound.These mechanistic results indicate that THF lowers the selectivity by interfering with chelation control, which is highly preferred in ether.Implications include the possibility of using other ethers to improve chelation/nonchelation control still more, or even use of chiral ethers as chiral controller groups or adjuncts.

Lithium Amino Alkoxide-Evans Enolate Mixed Aggregates: Aldol Addition with Matched and Mismatched Stereocontrol

Building on structural and mechanistic studies of lithiated enolates derived from acylated oxazolidinones (Evans enolates) and chiral lithiated amino alkoxides, we found that amino alkoxides amplify the enantioselectivity of aldol additions. The pairing of enantiomeric series affords matched and mismatched stereoselectivities. The structures of mixed tetramers showing 2:2 and 3:1 (alkoxide-rich) stoichiometries are determined spectroscopically. Rate and computational studies provide a viable mechanistic and stereochemical model based on the direct reaction of the 3:1 mixed tetramers, but they raise unanswered questions for the 2:2 mixed aggregates.

The chromium-reformatsky reaction: Anti-selective evans-type aldol reactions with excellent inverse induction at ambient temperature

anti-Aldol products are available in a two step, one pot reaction of 4-substituted oxazolidone, 2-bromopropionyl halide, chromium dichloride and an aldehyde. The diastereofacial selection (induction) is opposite to those of boron Evans enolates, i.e. the

Synthesis of γ-Lactones via the kowalski homologation reaction: Protecting-group-free divergent total syntheses of eupomatilones-2,5,6, and 3- epi-eupomatilone-6

A highly efficient synthesis of functionalized chiral γ-butyrolactone scaffolds has been described. The basis of the approach is the Kowalski ester homologation that is modified for our proposed transformation. The newly developed methodology combines a d

HIGHLY STEREOSELECTIVE REFORMATSKY REACTIONS OF 3-(2-BROMOPROPIONYL)-2-OXAZOLIDONE DERIVATIVES WITH VARIOUS ALDEHYDES

The Reformatsky reactions of 3-(2-bromopropionyl)-2-oxazolidone derivatives with various aldehydes were investigated to elucidate the effects of substituents in the 2-oxazolidone moieties on their diastereoselectivities.The highest 2,3-syn-diastereoselect

Extending the Scope of the Evans Asymmetric Aldol Reaction: Preparation of Anti and "Non-Evans" Syn Aldols

The Evans reagent, imide 1, reacts with aldehydes under Lewis acid catalysis to give anti or "non-Evans" syn aldols 5 or 6, depending on the reaction conditions.This discovery considerably amplifies the synthetic utility of these important reagents for asymmetric synthesis.

Asymmetric Aldol Reactions. Use of the Titanium Enolate of a Chiral N-Acyloxazolidinone To Reverse Diastereofacial Selectivities

Aldol reactions of the titanium enolate of (S)-N-propionyl-4-isopropyl-2-oxazolidinone (readily derived from L-valine) with representative aldehydes give high diastereofacial selectivities for the syn aldol adducts expected from chelation control.This represents a remarkable reversal in selectivity compared with the corresponding boron enolate, thus permitting either enantiomeric form of β-hydroxy-α-methyl carboxylic acids to be made from a single, readily available oxazolidinone simply by changing the metal.A lithium interference effect is shown to be easily prevented by use of excess titanium.Use of diethyl ether as solvent rather than THF significantly enhances the stereoselectivity.Mechanistically, the observed stereochemical reversal constitutes very strong evidence that chelation is operative with titanium, presumably through a chelated chairlike transition structure.In this transition structure, the conformation would be rigidly locked by chelation and the titanium would be at least hexacoordinate, resulting in a "superaxial" ligand, thus nicely explaining the high stereocontrol.

Reversal of Stereochemistry in the Aldol Reactions of a Chiral Boron Enolate

A novel route to optically active anti aldols of certain aldehydes is presented.The boron enolate derived from oxazolidinone 3 reacts with various aldehydes to give either syn or anti aldols, depending on the amount of dibutylboron triflate used in the en

APPARENT CHELATION IN ALDOL REACTIONS OF CHIRAL (Me2CHO)3Ti-ENOLATES

Directed aldol reactions of chiral (Me2CHO)3Ti-enolates give the opposite diastereofacial selectivity compared with the corresponding boron enolates.This stereochemical reversal is best explained if the Ti reactions involve chelation