2- Bromoallyl alcohol

We note that in this case the elimination products, that is, 2-bromo-3-chloropropene (BCP) and 2,3-dibromopropene (DBP), are allylic halides. Consequently, these both hydrolyze in relatively fast steps most likely via SN1 reactions (see the example given in Table 13.6) to form 2-bromoallyl alcohol (BAA). 

This reagent can be prepared by reaction of 2-bromoallyl alcohol in ether with 2.5 eq. of f-butyUithium at -78 to 0°. It reacts with carbonyl compounds to form, after hydrolysis, unsaturated diols of type (1) in 65-75% yield. ... 

Bromoallyl alcohol, 11 p-Bromoaniline, 229 2-Bromobenzoic acids, 144 6-Bromobenzpyrene, 316... 

An intermolecular addition of allylic alcohols CH2=CHCH(OH)R (R = H, alkyl) to alkynes R C=CR (R = alkyl, aryl, CH2CI R = C02Me, CH2CI, H), catalysed by PdCl2 with CuX2 as the stoichiometric oxidant, has been developed and shown to produce 1-bromo-1,4-dienes R2C(Br)C=C(R )CH2CH=CHRi as a result of a neat syn-bromoallylation of the C=C bond. ... 

Bromoboration Reactions. BBrj does not add to isolated double bonds, but reacts with allene spontaneously even at low temperature to give (2-bromoallyl)dibromoborane, which provides stable (2-bromoallyl)diphenoxyborane by the addition of anisole. The diphenoxyborane derivative reacts with carbonyl compounds to give 2-bromohomoallylic alcohols in high yields (eq 12). Bromoboration of 1-alkynes provides (Z)-(2-bromo-l-alkenyl)dibromoboranes stereo- and re-gioselectively (eq 13), which are applied for the synthesis of trisubstituted alkenes, a,p-unsaturated esters, and 7,8-unsaturated ketones, bromodienes, 1,2-dihalo-l-alkenes, 2-bromoalkanals, and (3-bromo-oi,3-unsaturated amides. ... 

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