## The synthesis is reported of three novel steroidal chiral auxiliaries (4) which were used to generate an a-hydroxy acid in high optical parity (90-9896 cc). Chiral auxiliaries for enantioselective syntheses are of current interest13 Cyclohexyl based chiial auxiliaries, such as menthol, S-phenyl
New cyclohexyl-based chiral auxiliaries: Enantioselective synthesis of α-hydroxy acids
✍ Scribed by Deevi Basavaiah; Peddinti Rama Krishna
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- French
- Weight
- 558 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0040-4020
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📜 SIMILAR VOLUMES
Chiral trichloromethyl carbinols 3, readily available by catalytic enantioselective redaction of trichloromethyl ketones, are converted with inversion of configuration into chiral aarylov and a-hydroxy carboxylic acid derivatives.
Five 0~-methyl carboxylic acids have been prepared with high e.e.s using 1,3-dithiane 1 -oxide (DiTOX) units as the stereocontrolling elements and sources of chirality.
The reduction of a variety of achiral ketones with catecholborane as stoichiometric reductant and 0.1 equiv of oxaxaborolidine 2 as catalyst in toluene at -78'C proceeds in > 95% yield and with enantioselectivities in the range 30: 1 to 9: 1, depending on substrate. This reduction procedure is espec