Asymmetric additions to carbonyl compounds

As mentioned earlier, the sulphoxide group is widely used in asymmettic synthesis. The final illustration of its use shows how it can direct the reduction of an adjacent carbonyl function as in (107) by complexation with the reducing agent, It is particularly useful 

The general and valuable Ehel method for the asymmettic synthesis of a-hydroxyaldehydes and other compounds is based on a 1,3- 

In principle, either enantiomer is available simply by reversing the order of the introduction of groups and R.  

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