196 REDUCTION WITH ALUMINUM ALKOXIDES . (LXVII) and benzyl isovanillin (LXVIII) have been obtained with less than one equivalent of aluminum isopropoxide. 47-48 With benzalde-hyde Wi ' 7 an exoessof reagent gives only 55-65% yields of benzyl alcohol 10 CHO LXVI with considerable benzyl benzoate resulting from the Tishchenko reac-tion. However, with only one-half an equivalent of reagent 37 an 89% yield of benzyl alcohol is obtained (Procedure II, p. 201), Apparatus The simplest type of apparatus, and one which is quite satisfactory except in the reduction of volatile ketones and aldehydes, consists of a round-bottomed flask equipped with a short reflux condenser (no water in the cooling jacket), attached at the top to another condenser set for distillation (see Procedure IV, p. 203). When the distillate no longer gives a test for acetone, the reduction is complete. If more than half of the solvent distils during the reaction it is advisable to add more iso-propyl alcohol to maintain the volume. If a concentrated solution is to
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This note was uploaded on 11/20/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.