Site-Selective Reactions of Malic Acid Derivatives

2 Site-Selective Reactions of Malic Acid Derivatives 

In order truly to unleash the synthetic potential of malic acid it is imperative that one be able to perform discrete operations at each of the four carbon centers of the molecule. Since malic acid by nature contains two nearly identical carboxylic acid groups, it is important to establish a way to differentiate between the two if one wishes to selectively manipulate either one. 

The chemistry discussed in this section illustrates various techniques used to manipulate each of the four carbon sites of malic acid derivatives, leading ultimately to useful chiral intermediates, biologically active compounds, or interesting natural products. 

This section focuses on the chemistry associated with the carboxyl group in the 1-position of malic acid derivatives. Manipulations such as selective hydrolysis, reduction, or cyclization 

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Site-Selective Reactions of Malic Acid Derivatives 203 OH OH... 

As we have just seen, hydrolysis of malic acid derivatives at the 1-position is relatively straightforward. But what if a chemist desires a malic acid half ester in which only the 4-carboxyl exists as a free acid Derivatives of this type are also accessible from L-malic acid through C-1 site-selective reactions. 

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