Sec-Butyl methyl ether

Ethers in which one of the groups is secondary begin to show appreciable cleavage at — 30°C. Protonated sec-butyl methyl ether 24 cleaves cleanly at — 30°C to protonated methanol and fert-butyl cation [Eq. (4.12)]. Ethers in which one of the alkyl groups is tertiary cleave rapidly even at —70°C. 

It was found possible to measure the kinetics of cleavage of protonated sec-butyl methyl ether 24 by following the disappearance of the methoxy doublet in the NMR spectrum with simultaneous formation of protonated methanol and ferf-butyl cation. The cleavage shows pseudo-first-order kinetics. Presumably, the rate-determining step is the formation of sec-butyl cation followed by rapid rearrangement to the more stable ferf-butyl cation... 

C5H10O2 isopropyl acetate 108-21-4 199.75 8.880 2 5847 C5H120 sec-butyl methyl ether 116783-23-4 154.48 7.658 2... 

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