Charette Asymmetric Cyclopropanation

Charette Asymmetric Cyclopropanation

  • General Characteristics

The Simmons-Smith cyclopropanation can be rendered asymmetric by using the chiral boronic acid ester as a reagent. An allylic hydroxyl group is needed in substrates as a directing group.

  • General References

  • Reaction Mechanism

charette_asym_cyclopro_2.gif

  • Examples

Asymmetric cyclopropanation of a conjugated diene in the synthesis of FR-900848.[1]

charette_asym_cyclopro_3.gif

An example in which cyclopropanation is done selectively for the alkene closer to the hydroxyl group.[2]

charette_asym_cyclopro_4.gif

  • Experimental Tips

  • References

[1] Barrett, A. G. M.; Doubleday, W. W.; Hamprechet, D.; Kasdorf, K.; Tustin, G. J.; White, A. J. P.; Williams, D. J. Chem. Commun. 1997, 1693. DOI: 10.1039/A700487G
[2] (a) Charette, A. B.; Juteau, H.; Lebel, H.; Deschenes, D. Tetrahedron Lett. 1996, 37, 7925. doi:10.1016/0040-4039(96)01798-4 (b) Charette, A. B.; Juteau, H. Tetrahedron 1997, 53, 16277. doi:10.1016/S0040-4020(97)01014-4

  • Related Reactions

Simmons-Smithシクロプロパン化

  • Related Books

  • External Links

, ,