Acyloin rearrangement 2-hydroxy ketones

A reaction similar in character to the base-catalysed acyloin rearrangement occurred when the i7a-hydroxy-20-ketone was heated in liquid ammonia [216]. The product, a i i mixture of i7a-epimeric amino-17-ketones (7) and (8) is best explained... 

The anion of the adduct of TMS-CN with benzaldehyde reacts with aldehydes and ketones to form acyloin silyl ethers, by way of a 1,4-0-silyl rearrangement (Scheme 10). This method gives a-hydroxy ketones in excellent yield (80-90%) and allows the selective synthesis of unsymmetrical benzoins. ... 

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