Tartaric acid, diethyl ester

Fig. 3.7. Definition of the enantiomeric excess ee using the Sharpless epoxidation of allylic alcohol as an example. The chiral auxiliary is tartaric acid diethyl ester (diethyl tartrate, DET).

CHIRAL MEDIA FOR ASYMMETRIC SOLVENT INDUCTIONS. (S,S)-(+)-l,4-BIS(DIMETHYLAMINO)-2,3-DIMETHOXYBUTANE FROM (R,R)-(+)-TARTARIC ACID DIETHYL ESTER... 

A wide variety of substituted y-butyrolactones can be prepared directly from olefins and aliphatic carboxylic acids by treatment with manganic acetate. This procedure is illustrated in the preparation of 7-( -OCTYL)-y-BUTYROLACTONE. Methods for the synthesis of chiral molecules are presently the target of intensive investigation. One such general method developed recently is the employment of certain chiral solvents as auxiliary agents in asymmetric synthesis. The preparation of (S.SM+H, 4-BIS(DIMETHYLAMINO)-2,3-DIMETHOXY-BUTANE FROM TARTARIC ACID DIETHYL ESTER provides a detailed procedure for the production of this useful chiral media an example of its utility in the synthesis of (+)-(/ )-l-PHENYL-l-PEN-TANOL from benzaldehyde and butyllithium is provided. 

Diethyl L-tartrate Tartaric acid, diethyl ester, L-(+)- (8) Butanedioic acid. 2,3-dihydroxy-, (R-(R, R )]-, diethyl ester (9) (87-91-2)... 

The first such process is a variant of the oxacyclo-propanation reaction discussed in Section 12-10, as applied specifically to 2-propenyl (allylic) alcohols. However, instead of a peroxycarboxylic acid, the reagent is ferf-butyl hydroperoxide in the presence of titanium (TV) isopropoxide ( Sharpless epoxidation ), the function of the chiral auxiliary being assumed by tartaric acid diethyl ester (Real Life 5-3). The naturally occurring (-l-)-[2/ ,3/ ]-diethyl tartrate and its nonnatural (—)-(25,35) mirror image are both commercial products. One delivers oxygen to one face of the double bond, the other to the opposite face, as shown below, giving either enantiomer of the oxacyclopropane product with high enantiomer excess (Section 5-2). 

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