110577-94-1

Upstream product

• 110577-90-7 (S)-3-((R)-2-Hydroxy-2-phenyl-pent-4-enoyl)-4-isobutyl-oxazolidin-2-one 
• 611-71-2 (R)-Mandelic Acid 
• 106-95-6 allyl bromide 
• 110577-86-1 1-((S)-4-Isobutyl-2-oxo-oxazolidin-3-yl)-2-phenyl-ethane-1,2-dione 
• 105457-91-8 2-oxo-2-(p-tolyl)acetyl chloride 
• 156365-91-2 (2S,4S,5R)-2-<(1R)-(1-hydroxy-1-phenyl)but-3-enyl>-4-methyl-5-phenyl-3-tert-butoxycarbonyloxazolidine 
• 156365-81-0 (2S,4S,5R)-4-methyl-2-(1-oxo-1-phenyl)methyl-5-phenyl-3-tert-butoxycarbonyloxazolidine 
• 1074-12-0 phenylglyoxal hydrate 
• 116907-30-3 (2R,5R)-2-(tert-butyl)-5-phenyl-1,3-dioxolan-4-one 

Relevant academic research and scientific papers

Asymmetric [2,3]-wittig rearrangement induced by a chiral carbanion whose chirality was transferred from an epoxide

(Chemical Equation Presented) The enantioselective [2,3]-Wittig rearrangement of 1-allyloxy-1-(naphthalen-2-yl)-4-siloxy-2,4-pentadienyl anion, derived from optically enriched 4,5-epoxy-1-(naphthalen-2-yl)-5-silyl-2-pentenyl allyl ether via a base-induced

Lipase AKG mediated resolutions of α,α-disubstituted 1,2-diols in organic solvents; remarkably high regio- and enantio-selectivity

Diols 1, which contain adjacent tertiary and primary hydroxy groups, can be selectively mono-acylated at the primary hydroxy group by many lipases in organic solvents. Since the reaction does not take place at the chiral tertiary centre itself, observed enantioselectivities are usually low. Only the combination of one lipase, lipase AKG (Amano, Pseudomonas sp.), with selected substrates gives high enantioselectivities (E 20 to > 200). Also, the solvent and acyl donor employed influences the outcome. On the basis of the results of lipase AKG towards substrates 1 an active site model for this specific lipase has been developed, which can account for the results obtained. Full experimental details on the synthesis of diols 1 and enzymatic preparation of acetates 2 are given. Also, the absolute stereochemistry of the enzymatically prepared diols 1 has been established by independent synthesis from (R)-mandelic acid.

N-Boc 2-acyloxazolidines: Useful precursors to enantiopure 1,2-diols via highly diastereoselective nucleophilic additions

N-Boc 2-Acyloxazolidines were synthesized from norephedrine and phenylglycinol. This preparation involves: (i) a transformation or the above β-amino alcohols into N-Boc 2-ethoxycarbonyloxazolidines, (ii) the formation of the corresponding Weinreb amides and, (iii) a reaction between these amides and organometallic reagents. Such diastereomerically pure heterocycles react cleanly with various nucleophilic reagents (Grignard reagents, sodium borohydride and allylsilane) to afford the corresponding alcohols. Treatment of these hydroxyoxazolidines with trifluoro acetic acid, followed by hydrolysis and reduction of the intermediate α-hydroxy aldehydes afforded 1,2-diols. The overall transformation exhibited in most cases a complete diastereoselectivity which can be explained by a chelated model for the nucleophilic addition.

Asymmetric Synthesis of Homochiral 1,2-Diols via N-Boc Oxazolidines

Diastereoisomerically pure N-Boc 2-acyloxazolidines were synthesized from phenylglyoxal and ethyl glyoxylate.Reaction of these heterocycles with Grignard reagents is highly stereoselective.Homochiral 1,2-diols were ultimately obtained after N-deprotection, hydrolysis and reduction of the intermediate α-hydroxy aldehyde.The asymmetric induction can be explained by a chelated model.

Asymmetric Synthesis of the Both Enantiomers of Tertiary Aryl Homoallyl Alcohols and Diols by Diastereoselective Addition of Allyltrimethylsilane to Chiral α-Keto Imides

Both enantiomers of homoallyl-alcohols and -diols are obtained in high enantiomeric excess (91 -> 98 e.e.) by titanium tetrachloride promoted diastereoselective addition of allyltrimethylsilane to chiral α-keto imides.