Oxidative cleavage, degradation reduction

An attempt to determine the absolute stereochemistry of natural eucomol (10) by chemical degradation to a product of known chirality led to a series of new transformations (64). It was anticipated that reduction of (10) to the deoxo derivative (58) followed by oxidative cleavage of ring A would lead to the lactone (59). From this intermediate the key compound (61) should be obtained by subsequent reduction. The derivative (61) is easily prepared from eucomic acid (60) whose absolute stereochemistry has been elucidated recently (34, 36). 

Redox mediators, such as flavins or quinones, are usually involved in the azo bond reduction. Therefore, the azo bond cleavage is a chemical, unspecific reaction that can occur inside or outside the cell, relying on the redox potential of the redox mediators and of the azo compounds. Also the reduction of the redox mediators can be both a chemical and an enzymatic process. As a consequence, it is an evidence that environmental conditions can affect the azo dyes degradation process extent both directly, depending on the reductive or oxidative status of the environment, and indirectly, influencing the microbial metabolism. 

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