Asymmetric synthesis of (R)-(+)-ethylmethyl-n-propylcarbinol in high enantiomeric purity. A 1,3-oxathiane derived from (+)-pulegone as chiral adjuvant
✍ Scribed by Ernest L. Eliel; Joseph E. Lynch
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- French
- Weight
- 237 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
SLunmary. A choral, conformatlonally locked 1,3-oxathiane has been prepared by 1,4-addition of benzyl mercaptan to (+)-pulegone followed by Na/NH3 reduction and condensation of the resulting hydroxythiol with paraformaldehyde. The utility of this chiral adjuvant is exemplified by the asymmetric synthesis of the title compound in 93% e.e.
In previous publications 1,2 we have descrtied highly (>95% e-e.) stereoselectlve asymmetric syntheses of C6H5C(CH3)0HCH0 (or the methoxy-acid derived therefrom) from a chiral 1,3-oxathlane.
However, the syntheses had various shortcomings. 1) Originally' the chiral adluvant (oxathiane)