@article{Hansen_1999, title={Otto Billeter oder wie die älteste [3,3]-sigmatrope Umlagerung nach Neuenburg kam: Teil1: Otto Billeter or How the Oldest [3,3]-Sigmatropic Rearrangement Went to Neuchâtel}, volume={53}, url={https://www.chimia.ch/chimia/article/view/1999_163}, DOI={10.2533/chimia.1999.163}, abstractNote={<p>A historical study on the early chemistry of organic isothiocyanates (mustard oil) and thiocyanates (rhodanides) is presented. The isomeric structures of these compounds were settled by the famous investigations of <em>August Wilhelm Hofmann</em> published in 1868. Another highlight in this early phase of structural chemistry was the discovery by <em>Otto Billeter</em> and independently by <em>Gustav Gerlich</em> that allyl thiocyanate rearranges thermally into mustard oil (allyl isothiocyanate). This rearrangement can be regarded as the oldest [3,3]-sigmatropic process realized nearly 40 years before <em>Ludwig Claisen</em> started his well-known investigation on the thermal rearrangement of allyl phenyl ethers. The further development of the chemistry of thiocyanates and isothiocyanates will be discussed in the second part of this study.</p>}, number={4}, journal={CHIMIA}, author={Hansen, Hans-Jürgen}, year={1999}, month={Apr.}, pages={163} }