152 PRACTICAL ORGANIC CHEMISTRY pounds of the pinacol type. Dissolve i g. of powdered benzophenone in 6-7 ml. of cold isopropanol with shaking, add i drop of glacial acetic acid, and then confine the solution either in a glass receiver having a ground-glass stopper, or in a tube which is sealed 2(C 6 H^) 1 CO -> (C 6 H 6 ) t C(OH)-C(OH) (C«H 5 ), or closed with a tightly fitting rubber bung. Place the container on a window-ledge in full daylight and (if possible!) in sunlight. Within a few days in summer (and 2-3 weeks in winter), crystals of tetraphenylethylene glycol separate. Filter these off, and recrystallise from ethanol. M. p. 189°. Pinacolone. (CH 8 ) 3 C'COCH 3 The Pinacol-Pinacolone Rearrangement. When pinacol is warmed with acids, it undergoes rearrangement to pina-colone, with an over-all loss of one molecule of water. This rearrangement is general for i,2-diols of the type R 2 C(OH)-C(OH)-R 2 where the groups R may be alike or different, and may be alkyl or aryl groups. R
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.