Plattner process

G. Rokey and B. Plattner, Process Description Full Fat Soy, Wenger Manufacturing, Sabetha, Kansas, 2001. 

The manufacturing process as described in U.S. Patent 3,170,936 uses the readily available methyl 3/3-hydroxy-17a-methyl-A -etienate (I), described by Plattner in He/v. Chim. Acta, vol. 31, p 603 (1948), as the starting material. The etienic acid ester (I) may also be called 17a-methyl-17/3-carbomethoxyandrost-5-ene-3/3-ol. 

Plattner An early process for extracting gold from auriferous pyrites by chlorination. The resulting gold chloride is extracted by water and reduced with ferrous sulfate ... 

Plattner E, Comninellis Ch (1988) In Stucki S (ed), Process technicology for water treatment, Plenum Press, p 205... 

Comninellis Ch, Plattner E (1987) Symp Process technology for water treatment, BBC Research Center Baden (Switzerland), Sept 21/22... 

Strong preference for chair over twist boat development appears to be general, and is often referred to as the rule of diaxial opening or the Furst-Plattner rule. Twist boat processes can be encouraged by suitable substitution, but in the absence of such special features there are no known examples of cyclohexene oxides which give appreciable amounts of twist boat opened products (sometimes called diequatorial-opening products). The lone apparent exception has been shown to be an artifact caused by an impurity. 

Heuer, C., Kiisters, E., Plattner, T., Seidel-Morgenstem, A. Design of the simulated moving bed process based on adsorption isotherm measurements using a perturbation method, J. Chromatogr. A, 1998, 827, 175-191. 

Plattner, E. and Comninellis, C. In S. Stucki (ed.), Process Technologies for Water Treatment. Plenum, New York, 1988. 

The proposed mechanism of the process includes a quasi-Favorskii rearrangement, as illustrated in Scheme 73 for the transformation of 117 into 118. Attack of bromide on the epoxide is expected to occur in a trans diaxial fashion, in accord with the Fiirst-Plattner rule, at the position of the epoxide distal to the electron-withdrawing hydroxyl group. The immediate result of this ring opening would be 121, which is in rapid conformational equilibrium with 122. Migration of a o bond from this latter conformation with concomitant expulsion of bromide would give 123, which dehydrates to afford the observed product... 

The observation that the methylative ring opening of the cis-epoxide 56 did not, according to the Furst-Plattner rule, take place at C3 (trans-diaxial process) but at C4 to provide 58 could be explained by the less stable but chelation-supported 56a. To prove this effect, the reaction was reran but this time in the presence of a crown ether to sweep all the cations from the solution. 

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