A short enantioselective synthesis of (+)-L-733,060 via Shi epoxidation of a homoallylic carboxylate
โ Scribed by Lourdusamy Emmanuvel; Arumugam Sudalai
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- French
- Weight
- 154 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0040-4039
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โฆ Synopsis
A short and efficient enantioselective synthesis of (+)-L-733,060 in 92% ee via Shi epoxidation of a homoallylic carboxylate is described. Johnson-Claisen rearrangement was employed to obtain the required carbon backbone, whilst intramolecular reductive O-to-N-ring expansion of a d-azidolactone was used in the construction of the piperidine moiety.
๐ SIMILAR VOLUMES
A short and high yielding enantioselective synthesis of (ร)-bestatin, a naturally occurring aminopeptidase inhibitor, is described via L-proline-catalyzed asymmetric a-amination of 3-phenylpropionaldehyde as the key reaction. The methodology also involves a Pd-catalyzed intramolecular cyclization of
Diazoketone 5b, available in one step from proline benzyl ester, underwent conversion to quinolizidine gb with high diastereoseleOivity (19:1 gb/Tb) and in sm~risingly high enanfiomeric excess (75%). The key step presumably occurs via spirocyclic ylide 6b, which undergoes [l,2]-shift with retention.