Diaxial-diequatorial rearrangement

Without additional reagents Diaxial-diequatorial rearrangement with positional interchange of arylthio and sulfonyl groups... 

Dictatorial s. Diaxial-diequatorial rearrangement Dietbylalnminam chloride as reagent 27,142 28,658... 

For a related example of diaxial to diequatorial rearrangement which illustrates the expected transposition of the vicinal substituents see S. Hanessian and A. P. A. Staub, Carbohydr. Res., 1970,14, 424. 

Wiest and Houk" " examined the Claisen rearrangement that takes 1 into 2 in the gas phase at B3LYP/6-31G. The geometries of the diequatorial and diaxial form of 1, the TS 3, and the product 2 are shown in Figure 9.4. The diequatorial form is more stable than the diaxial form, by 12 kcal mol at B3LYP/6-31G, ... 

The conditions necessary for rearrangement of 2/3,3a-(diaxial) iodohydrin esters [e.g. (28)] to the transposed diequatorial isomers [e.g. (29)] have been further... 

Analogously, the diaxial dibromides formed preferentially from unsaturated steroids in kinetically controlled reactions rearrange to the diequatorial dibromides.66... 

N.m.r. evidence obtained at 250 MHz has been used to show that the trans-triaxial-2,3,6-tribromo-4-methylcyclohexanone (lOa) undergoes a spontaneous dyo-tropic rearrangement in the solid state to give the trans-diequatorial isomer (10b). From the n.m.r. parameters it was concluded that the triaxial isomer is somewhat deformed by syn-diaxial interactions of the bromine atoms. 

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