Methyl separation

The distillate weighs about 110 g. and contains methyl formate and methylal. If it is placed in a flask provided with a reflux condenser and a solution of 25 g. of sodium hydroxide in 40 ml. of water is added, the methyl formate is liydrolysed to sodium formate and the methylal separates on the surface. The latter may be removed, dried with anhydrous calcium chloride and distilled about 30 g. of methylal, b.p. 37-42°, are obtained. If the aqueous layer is evaporated to diyness, about 25 g. of sodium formate are isolated. 

According to what may be called the methyl separation mechanism, the polymerization reaction involves the rupture of a carbon-carbon bond of the olefin to give a methyl and an olefin radical which then add to the double bond of another olefin molecule (Kline and Drake, 60). The molecule of isobutylene, for example, behaves as though it were activated in the following manner CHa-+C(CH3)=CH2. The positive and negative signs indicate the relative electronegativities (Kharasch, 61) and are not intended to indicate ionization. The addi-... 

Since 2,4,4-trimethyl-l-pentene is obtained in about four times the amount as is 2,4,4-trimethyl-2-pentene it may be assumed that the activation takes place 80% by methyl separation and 20% by hydrogen separation. 

One objection to the methyl separation mechanism is that it does not take into consideration the role of the catalyst. Another is that no rules have been set up which would permit the choice of which olefins act as acceptors or which are activated. There is no way of determining which of a number of possible compounds will be those actually obtained ... 

As was shown above, only the latter is obtained when sec-butyl alcohol is treated with 75% sulfuric acid at 80° under pressure. It is significant to note that this shortcoming of the methyl separation mechanism as compared to the carbonium ion mechanism was pointed out in a later paper (Drake and Veitch, Jr., 30) by one of the original proponents of the methyl separation mechanism. 

The less soluble chloroalkanoic acids (R larger than methyl) separate from the solution as an oil. 

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