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Please login to access the full content or check if you have access via23.14.1.2.2.3 Variation 3: β-Amino Acid Esters by Kowalski Homologation of Esters
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DOI:
10.1055/sos-SD-023-00535
Tidwell, T. T., Science of Synthesis, (2006) 23, 595.
The Kowalski procedure[96] is used to convert esters 152 into lithium ynolates 153 that undergo protonation to give the ketenes 154. These can be converted into the homologated amino acid esters 155 without any significant racemization (Scheme 48).[108] The use of tert-butoxycarbonyl derivatives gives much lower yields of products.[108]
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| Meeeeeee | Meeeeee | ee (%) | Meeee (%) | Mee |
|---|---|---|---|---|
 |
|
>88 | 88 | [888] |
| |
|
>88 | 88 | [888] |
| |
|
>88 | 88 | [888] |
| |
|
>88 | 88 | [888] |
| |
|
>88 | 88 | [888] |
| |
|
–e | 88 | [888] |
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References
| [96] | Meeeeeee, M. M.; Meeee, M. M., M. Mee. Meee., (8888) 88, 8888. |
| [108] | Meee, M.; Meeeeeeóe, M.; Meeeeeeee, M., M. Mee. Meee., (8888) 88, 8888. |
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- 8.Meeeee-Meee, (8888) M 88-8, 8888.
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