2-Ethoxy-3-methylbutane

An example of a reaction with rearrangement is the SnI reaction of 2-bromo-3-methylbutane in boiling ethanol. The product is a mixture of 2-ethoxy-3-methylbutane (not rearranged) and 2-ethoxy-2-methylbutane (rearranged). 

Give the SN1 mechanism for the formation of 2-ethoxy-3-methylbutane, the unrearranged product in this reaction. 

Ethoxy 2 methylbutane (Major product in absence of sodium ethoxide)... 

The rearranged product, 2-ethoxy-2-methylbutane, results from a hydride shift, the movement of a hydrogen atom with its bonding pair of electrons. A hydride shift is represented by the symbol H. In this case, the hydride shift converts the initially formed secondary carbocation to a more stable tertiary carbocation. Attack by the solvent gives the rearranged product. 

C7H15CI 2-chloro-5-methyl hexane 58766-17-9 14.933 156.789 1,2 12213 C7H160 2-ethoxy-2-methylbutane 919-94-8 14.482 155.928 1.2... 

Further studies on the Cj + Cj route to rose oxide (909) mentioned in Vol. 4 (p. 565, Ref. 773) include the radical addition of 3-methyl-3-butenyl acetate to 3-ethoxy-3-methylbutanal. This led to 40% of the ketone 926, which can be converted to rose oxides (cis/trans 9 1) by reduction (NaBH4), hydrolysis, and acid cyclization. °° Russian workers have examined (and with variously substituted homologs) the reaction between 3-methylbutanal (82) and 4,4-... 

CsHjoO C7Hi,0 2-Ethoxy-2-methylbutane Propyl acetate 371.15 0.4764 100.21 ox... 

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