100791-76-2

Upstream product

• 13171-64-7 Dimethyl D-tartrate 
• 121-97-1 4-Methoxypropiophenone 
• 608-68-4 dimethyl L-tartrate 
• 497-19-8 sodium carbonate 
• 149-73-5 trimethyl orthoformate 

Downstream Products

• 100791-83-1 Dimethyl (4R,5R)-2-[(S)-1-bromoethyl]-2-(4-methoxyphenyl)-1,3-dioxolane-4,5-dicarboxylate 
• 100791-84-2 Dimethyl (4R,5R)-2-[(R)-1-bromoethyl]-2-(4-methoxyphenyl)-1,3-dioxolane-4,5-dicarboxylate 
• 100791-83-1 (4S,5S)-2-((S)-1-Bromo-ethyl)-2-(4-methoxy-phenyl)-[1,3]dioxolane-4,5-dicarboxylic acid dimethyl ester 
• 100791-83-1 (4S,5S)-2-((R)-1-Bromo-ethyl)-2-(4-methoxy-phenyl)-[1,3]dioxolane-4,5-dicarboxylic acid dimethyl ester 

Relevant academic research and scientific papers

Enantioselective synthesis of α-bromo acid derivatives and bromohydrins from tartrate derived bromoacetals

Bromination of the acetals 4 derived from aryl alkyl ketones, ArCOR, and (2R,3R)-tartaric acid results in bromoacetals 5 with 78-90% de. Hydrolysis of those compounds with Ar = 4-methoxyphenyl or 3-bromo-4-methoxyphenyl results, after recrystallisation, in α-bromoketones 8 with 66-98% ee which are shown to undergo the Baeyer-Villiger oxidation to α-bromoesters 9 with minimal racemisation, α-Bromoketone 8d is shown to undergo carbonyl reduction to threo-bromohydrin 15 with retention of stereochemistry.

Process for the preparation of optically active alpha-acrylalkanoic acids and novel intermediates thereof

A new enantioselective process is described for preparing optically active alpha-arylalkanoic acids by: (a) halogenation on the aliphatic carbon atom alpha to the ketal group, of ketals of formula STR1 in which Ar represents an aryl, optionally substituted; R represents a C1 -C4 alkyl; R1 and R2, represents a hydroxy, a O- M+, OR3 or NR4 R5 group; the carbon atoms indicated by an asterisk both simultaneously are in (R) or (S) configuration. This reaction is diastereoselective, so that a mixture of alpha-haloketals is obtained in which one of the two epimers prevails, and generally strongly prevails, over the other. (b) rearrangement of the haloketals of formula STR2 in which X is Cl, Br or I to alpha-arylalkanoic acids in a single stage or in two successive stages, by way of esters of formula STR3 The compounds (A) and (C) are all new compounds. The rearrangement step (b) may be performed under new, inventive conditions. The esters of formula (C) have pharmacological activity analogous to that of the corresponding alpha-arylalkanoic acids.

Tartaric Acid, an Efficient Chiral Auxiliary: New Asymmetric Synthesis of 2-Alkyl-2-arylacetic Acids

A highly enantioselective synthesis of 2-alkyl-2-arylacetic acids, an important class of antiinflammatory agents, based on a new diastereoselective α-bromination of homochiral acetals 1 and on the stereospecific silver-promoted rearrangement of the corresponding homochiral α-bromo acetals 2 and 3, is reported.The new methodology represents a meaningful example of the use of tartaric acid as efficient and economic chiral auxiliary.The asymmetric bromination of 1 is of general character and occurs with very high diastereoselectivity, even at room temperature; a mechanism for the new reaction is proposed.The overall process has been successfully applied to the preparation of enantiomerically pure 2-alkyl-2-arylacetic acids, among them (2S)-(+)-2-(6-methoxy-2-naphthyl)propanoic acid (Naproxen)