L,2-Epoxy-2-methylpropane

Lithium aluminum hydride reduction of l,2-epoxy-2-methylpropane gives, as expected, predominantly tert-butyl alcohol. 

Although EO polymerization can be achieved quite rapidly (reaction half-time is about 30 min at room temperature for [EO]/[(TPP)AlCl] =400 in dichloromethane), other epoxides show a lower reactivity. In similar conditions, it requires several hours for POx and 1,2-epoxybutane (BOx), ° whereas for styrene oxide or l,2-epoxy-2-methylpropane conversions do not exceed 15% after 8 days of reaction (Table 7). ° ... 

The isolation of the non-cyclic amino(aryl)carbenes and amino(alkyl)car-benes demonstrated that singlet carbene centers can be sufficiently stabilized by only one a-nitrogen atom. In 2005, Bertrand and co vorkers succeeded in preparing the first cyclic alkyl(amino)carbenes (CAACs, Scheme 1.15). The precursor for CAAC 123 was obtained from an imine by deprotonation with LDA (LDA = lithium diisopropylamide) and subsequent reaction with l,2-epoxy-2-methylpropane to give 121, which was converted into cyclic aldirain-ium salt 122 by reaction with trifluoromethanesulfonic acid anhydride. Deprotonation of 122 with LDA afforded CAAC 123 as a colorless solid (Scheme 1.15). 

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