11- Bromo-l-undecene

An interesting study on the synthesis of polyethylene (PE) mimics derived from fatty-acid derivatives and thiol-ene polymerisation [39] involved preparation of two different diene monomers from a commercially available derivative of undecenoic acid, 11-bromo-l-undecene, and 10-undecenol for the synthesis of a series of non-biodegradable polymers (Scheme 6.13). The authors considered these non-biodegradable polymers to be renewable plant oil-derived substitutes for PE. 

The first synthesis for methyl (Z)-2-methoxy-6-hexadecenoate was reported by Soderquist et al. [35]. The idea behind the construction of the a-methoxy functionality was the addition of a carboxy synthon to the corresponding aldehyde, in this case 5- pentadecenal, followed by methylation of the hydroxy group. This synthesis started with the Suzuki-Miyaura cross coupling of 4-bromo-l-butyl-9-borabicyclononane with (Z)-l-bromo-l-undecene, prepared as shown in Fig. (11). 

The hydroalumination of terminal alkenes and dienes using BujAl as aluminum source can also be catalyzed by late transition metal complexes such as (PPh3)2PdCl2 [38]. The reactions are carried out at room temperature, the use of dichloromethane as a solvent is crucial because it probably regenerates the catalytically active Pd(II) species by reoxidizing Pd(0) complexes formed in side reactions. Internal C=C bonds are not hydroaluminated under these conditions. Functional groups such as Cl, Br, and PhS in a position remote to the terminal C=C bond are tolerated, however, certain substrates such as 4-bromo-l-butene, 11-iodo-l-undecene, allyl phenyl ether, allyl benzyl ether, and (3 )-l,3-decadiene did not provide the desired hydroa-... 

An intermediate esterification is required to achieve anti-Markovnikov addition of HBr to higher unsaturated alcohols. For instance, even when a peroxide is added, 10-undecen-l-ol and HBr afford 10-bromo-l-undecanol, whereas HBr adds to 10-undecenyl acetate in the presence of peroxides so that the bromine appears in the 11-position whereas in the presence of antioxidants (H2 and diphenylamine) it appears in the 10-position.200 The HBr adducts obtained from the acetates in the presence of dibenzoyl peroxide can be converted into the bromo alcohols by transesterification with methanol and / -toluenesulfonic acid.201 11-Bromo-1-undecanol, 13-bromo-l-tridecanol, and 15-bromo-l-pentadecan ol can also be obtained by intermediate conversion of the corresponding co-unsaturated alcohols into the boric esters. 

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