Homoallylic azides

Pyrrolidines. Homoallylic azides react with the chloroboranes to afford... 

Steroids which contain a homoallylic structural unit produce an even greater multiplicity of products by both S nI and Sjf2 interactions with azide ion This point is best illustrated by reference to... 

Pentenenitriles and benzo[f]indoles. Ally iminophosphoranes are formed from the corresponding azides upon treatment with PPh j (Staudinger reaction). Condensation of these products with diaryl ketenes leads to 4-pentenenitriles by a sig-matropic rearrangement. In the homoallyl series the Wittig reaction is followed by an intramolecular Diels-Alder reaction. Mild dehydrogenation of the products gives ben zo[/] indoles. ... 

On the other hand, the couphng of methyl (Z)-2-(bromomethyl)-2-butenoate with the aldehyde under the same conditions generated the desired homoallylic alcohol in 80% yield with a high 93 7 syn/anti selectivity (Eq. 4.21). The indium-mediated aUylation of triflu-oroacetaldehyde hydrate (R = H) or trifluoroacetaldehyde ethyl hemiacetal (R = Et) with an aUyl bromide in water yielded a-trifluoromethylated alcohols. Lanthanum triflate-promoted indium-mediated allylations of aminoaldehydes in aqueous media generated j8-aminoalcohols stereoselectively. Indium-mediated intramolecular carbocychzation in aqueous media generated fused Q -methylene-y-butyrolactones. An advanced intermediate for azaspiracids was only accessible by the indium-mediated aUylation. Other potentially reactive functionalities, such as azide, enone, and ketone, did not interfere with the reaction. 

---