Simmons-Smith reaction
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The Simmons-Smith reaction is an organic reaction in which a carbenoid reacts with an alkene (or alkyne) to form a cyclopropane. Thus, cyclohexene, methylene iodide, and a zinc-copper couple (as (iodomethyl)zinc iodide, ICH2ZnI) yield bicyclo[4.1.0]heptane.
Alternatively, diethylzinc is used instead of the zinc-copper couple.
The Simmons-Smith reaction is generally subject to steric effects, and thus cyclopropanation usually takes place on the less hindered face. However, when hydroxy substituents are present on chiral carbons, the zinc coordinates with the hydroxy substituents, directing cyclopropanation to the same face, which may or may not be sterically favorable .
[edit] References
- ↑ Simmons, H.E.; Smith, R.D. J. Am. Chem. Soc., 1958, 80, 5323.
- ↑ Simmons, H.E.; Smith, R.D. J. Am. Chem. Soc., 1959, 81, 4256.
- ↑ Denis, J.M.; Girard, J.M.; Conia, J.M. Synthesis, 1972, 549.
- ↑ Smith, R. D.; Simmons, H. E. Organic Syntheses, Coll. Vol. 5, p.855 (1973); Vol. 41, p.72 (1961). (Article)
- ↑ Ito, Y.; Fujii, S.; Nakatuska, M.; Kawamoto, F.; Saegusa, T. Organic Syntheses, Coll. Vol. 6, p.327 (1988); Vol. 59, p.113 (1979). (Article)
- ↑ Simmons, H. E. et al. Org. React. 1973, 20, 1. (Review)
- ↑ Girard, C.; Conia, J. M. J. Chem. Res. (S) 1978, 182. (Review)
- ↑ Grieco et al. J. Org. Chem. 1977, 42, 4113.
