Allylic compounds Methyllithium

Allylic phosphorus compounds Tris(tetrabutylammonium) pyrophosphate, 338 Allylsilanes t-Butyllithium, 58 Chlorotrimethylsilane-Lithium, 81 Lithium bis(dimethylphenylsilyl)-cuprate, 161 Methyllithium, 188 Trichlorosilane-t-Amines, 322 Allylic sulfur compounds (Phenylsulfonyl)allene, 247 Sodium benzenesulfinate, 289... 

The rest of the synthesis (Scheme 13) is completely stereospecific and most of the steps are known (20). The bicyclic acid was oxidatively decarboxylated with lead tetraacetate and copper acetate (21). The resulting enone was alkylated with methyllithium giving a single crystalline allylic tertiary alcohol. This compound was cleaved with osmium tetroxide and sodium periodate. Inverse addition of the Wittig reagent effected methylenation in 85% yield. Finally, the acid was reduced with lithium aluminum hydride to grandisol. 

A final point regards the effect of lithium salts. Methyltitanium triisopropoxide 6, prepared from methyllithium and 3, reacts in situ with carbonyl compounds lightly slower than the distilled compound. However, this has no effect on chemoselectivity6. The only exception noted so far concerns allyl derivatives, as discussed in the following Section C.VII. 

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