Abstract
The asymmetric aldol reaction of 1,2-diketones, masked as nonracemic 2-acyl dithiane oxides, with lithium enolates derived from several esters and lactones, proceeds with a high degree of stereocontrol at both carbonyl and enolate prochiral centers, the stereocontrol mainly determined by the configuration of the sulfoxide sulfur atom. The sense of induced stereochemistry observed for ester enolates is different from that seen for lactone enolates. Hydrolysis of the dithiane oxide units of the major diastereoisomerically pure aldol products affords enantiomerically pure tertiary alpha-substituted beta-hydroxy-gamma-ketoesters.
Original language | English |
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Pages (from-to) | 6027-6034 |
Number of pages | 8 |
Journal | Journal of Organic Chemistry |
Volume | 65 |
Issue number | 19 |
DOIs | |
Publication status | Published - 2000 |
Keywords
- ASYMMETRIC BUILDING-BLOCK
- C-2-SYMMETRICAL
- 3-DITHIANE 1-OXIDES
- 2-ACYL-1
- ENOLSILANES
- GRIGNARD-REAGENTS
- 1
- 3-DITHIANE 1-OXIDE
- CHIRAL LEWIS-ACIDS
- DERIVATIVES
- PYRUVATE ESTERS
- COPPER(II) COMPLEXES
- ADDITIONS