Bamford-Stevens reaction

The Bamford-Stevens reaction is a chemical reaction whereby treatment of tosylhydrazones with strong base gives alkenes.^[1][2][3] It is named for the British chemist William Randall Bamford and the Scottish chemist Thomas Stevens Stevens (1900-2000). The usage of aprotic solvents gives predominantly Z-alkenes, while protic solvent gives a mixture of E- and Z-alkenes.

Additional recommended knowledge

Essential Laboratory Skills Guide

Daily Sensitivity Test

What is the Correct Way to Check Repeatability in Balances?

The treatment of tosylhydrazones with alkyl lithium reagents is called the Shapiro reaction.

Reaction mechanism

The first step of the Bamford-Stevens reaction is the formation of the diazo compound 3.^[4]

In protic solvents, the diazo compound 3 decomposes to the carbenium ion 5.

In aprotic solvents, the diazo compound 3 decomposes to the carbene 7.

References

1. ^ Bamford, W. R.; Stevens, T. S. (1952). "The decomposition of toluene-p-sulfonylhydrazones by alkali". J. Chem. Soc.: 4735–4740. doi:10.1039/JR9520004735.
2. ^ Shapiro, R. H. (March 1976). "Alkenes from Tosylhydrazones", Organic Reactions, 405–507. ISBN 0-471-19624-X. 
3. ^ Adlington, R. M.; Barrett, A. G. M. (1983). "Recent applications of the Shapiro reaction". Acc. Chem. Res. 16 (2): 55–59. doi:10.1021/ar00086a004.
4. ^ Creary, X. (1986). "Tosylhydrazone salt pyrolises: phenyldiazomethanes". Organic Syntheses 64: 207. (also in the Collective Volume (1990) 7:438 (PDF))

See also

• Shapiro reaction