Abstract
N,N-Dialkyl-2-formylbenzamides and N,N-dialkyl-2-formyl-1-naphthamides condense with (-)-ephedrine in refluxing toluene to give oxazolidines both as single diastereoisomers with respect to the new stereogenic centre and as single conformers with respect to the slowly-rotating Ar-CONR2 bond. In the naphthamide series, removal of the ephedrine auxiliary by hydrolysis returns the starting aldehyde (isolated by reduction to the more stable alcohol) in enantiomerically enriched form (up to 94% ee). Overall, the two-step sequence amounts to a dynamic resolution under thermodynamic control. © 2001 Elsevier Science Ltd.
| Original language | English |
|---|---|
| Pages (from-to) | 3163-3166 |
| Number of pages | 3 |
| Journal | Tetrahedron Letters |
| Volume | 42 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - 30 Apr 2001 |
Keywords
- Atropisomers ((-)-ephedrine as an auxiliary for the asym. synthesis of atropisomeric amides by dynamic resoln. under thermodn. control); Amides Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) ((-)-ephedrine as an auxiliary for the asym. synthesis of atropisomeric amides by dynamic resoln. under thermodn. control); Resolution (kinetic; (-)-ephedrine as an auxiliary for the asym. synthesis of atropisomeric amides by dynamic resoln. under thermodn. control)