The direct proline-catalyzedasymmetric α-aminoxylation of aldehydes and ketones has been developed using nitrosobenzene as an oxygen source, affording α-anilinoxy-aldehydes and -ketones with excellent enantioselectivity. Reaction conditions have been optimized, and low temperature (−20 °C) was found to be a key for the successful α-aminoxylation of aldehydes, while slow addition of nitrosobenzene
Synthesis of Optically Pure Compounds by Enantiotopically Differentiating Monoacetalization of Prochiral Diketones. Part II. Fragmentation of ?-Keto-Acetals
作者:Rudolf O. Duthaler、Peter Maienfisch
DOI:10.1002/hlca.19840670324
日期:1984.5.2
sulfonate counter-ion. Application of this reaction to the diastereomeric monoacetals 3 and 4, derived from cis-9-methyl-decalin-1,8-dione (1), followed by transesterification with CH3OH, yields opticallypure 4-(2′-methyl-3′-oxocyclohexyl)butyrate 9 ((+)−9 from 3, (−)-9 from 4) and the monosulfonate of Meso-2,3-butanediol (−)-13 (Scheme 2). Unexpectedly, this cleavage proceeds as well with monoacetal