Zusammenfassung
The 1,2-diol unit occurs frequently in natural products, such as carbohydrates, polyketides, and alkaloids, and the development of enantioselective methodologies for its preparation has been at the forefront of modern catalytic asymmetric synthesis. While the syn-1,2-diol unit may be considered a “clearable”1 stereochemical element due to the Sharpless asymmetric dihydroxylation (AD) of (E)-olefins,2 the diastereomeric anti-1,2-diols are far less accessible, mainly because the corresponding (Z)-olefins are more difficult to obtain and show reduced enantioselectivity in the AD. In this paper we disclose a novel, highly diastereo-, and enantioselective catalytic synthesis of anti-1,2-diols that is based on the proline-catalyzed direct asymmetric aldol reaction.
