A method is described for the synthesis of oxetan-2-ones comprising protection of the hydroxy group of an hydroxy ester with an acid-labile acetal protecting group, reduction of this O-protected hydroxy ester to an O-protected hydroxy aldehyde, condensation of this aldehyde with a metal enolate of an activated carboxylic acid derivative and spontaneous deprotection of the hydroxy group during the acidic workup procedure. Using the new O-protected hydroxy aldehydes as intermediates the oxetan-2-ones can be obtained after separation in diastereomerically and enantiomerically pure form, in a remarkably reduced number of steps, and in a significantly improved overall yield.
本文描述了一种合成
噁唑烷-2-酮的方法,包括使用酸敏感的
缩醛保护基保护羟基酯基,将该O-保护羟基酯基还原为O-保护羟基醛,将该醛与激活的
羧酸衍
生物的
金属烯醇缩合,然后在酸性工作程序中自发去除羟基保护基。使用新的O-保护羟基醛作为中间体,可以在显著减少的步骤数和显著提高的总收率下,以对映异构体和对映体纯的形式分离得到
噁唑烷-2-酮。