Aluminum, tris reactions with acyclic enones

For example, when acyclic enones are exposed to tris(trimethylsilyl)aluminum (7) at room temperature, only the 1,2-addition product is observed, whereas the addition proceeds via a 1,4-addition process when the reaction is conducted at -78 C (compare entries 8 and 9 in Table 5). In contrast, a, -unsatu-rated aldehyde substrates only undergo 1,2-additions with reagent (7). 

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