3- substituted primary alcohol resolution

In combination with a Burkholderia cepacia lipase (PS-D I) for the kinetic resolution, various primary alcohols were converted into the corresponding enan-tiomerically pure esters in high yields (70-87%) and ee values ranging from 70% to 99% (17). The protocol was found applicable to both alkyl- and aiyl-substituted primary alcohols. 

The AE reaction has been applied to a large number of diverse allylic alcohols. Illustration of the synthetic utility of substrates with a primary alcohol is presented by substitution pattern on the olefin and will follow the format used in previous reviews by Sharpless but with more current examples. Epoxidation of substrates bearing a chiral secondary alcohol is presented in the context of a kinetic resolution or a match versus mismatch with the chiral ligand. Epoxidation of substrates bearing a tertiary alcohol is not presented, as this class of substrate reacts extremely slowly. 

A similar chiral substituent effect is also observed in kinetic resolution of racemic primary allylic alcohols (Scheme 8). For example, both the enantiomers of racemic E-allylic alcohol are epoxidized at almost the same rate, while efficient kinetic resolution occurs in the epoxidation of racemic Z- and 2-substitut-ed allylic alcohols [49]. 

Enzymatic oxidations of carbon-nitrogen bonds are as diverse as the substances containing this structural element. Mainly amine and amino acid oxidases are reported for the oxidation of C-N bonds. The steroespecificity of amine-oxidizing enzymes can be exploited to perform resolutions and even deracemizations or stereoinversions (Fig. 16.7-1 A). Analogous to the oxidation of alcohols, primary amines are oxidized to the corresponding imines, which can hydrolyze and react with unreacted amines (Fig. 16.7-1 B). In contrast to ethers, internal C-N bonds are readily oxidized, yielding substituted imines. This can be exploited for the production of substituted pyridines (Fig. 16.7-1 C). Furthermore, pyridines can be oxidized not only to N-oxides but also to a-hydroxylated products (Fig. 16.7-1 D). 

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