Biotin Synthesis Sulfur Preempts a Beckmann Rearrangement

Biotin Synthesis Sulfur Preempts a Beckmann Rearrangement 

During an elegant synthesis of biotin the oxime 1 was treated with thionyl chloride at 0°C in the expectation that Beckmann rearrangement would occur. The product, however, was found to be 2(75%). 

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