Sucrose, telomerization with butadiene

As compared to the esterification of sucrose, cataly tic etherification of sucrose provides another family of non-ionic surfactants that are much more robust than sucrose esters in the presence of water. Synthesis of sucroethers can be achieved according to two processes (1) the ring opening of epoxide in the presence of a basic catalyst and (2) the telomerization of butadiene with sucrose using a palladium-phosphine catalyst. 

Table 11 Telomerization of butadiene (1) with sucrose (20) in water-based solutions...

Other Alkyl Ethers. Sucrose has been selectively etherified by electrochemical means to generate a sucrose anion followed by reaction with an alkyl halide (21,22). The benzylation of sucrose using this technique gives 2-O-benzyl- (49%), T-O-benzyl- (41%), and 3 -O-benzyl- (10%) sucrose (22). The benzylation of sucrose with benzyl bromide and silver oxide in DMF also produces the 2-O-benzyl ether as the principal product, but smaller proportions of T- and 3 -ethers (23). Octadienyl ether derivatives of sucrose, intermediates for polymers, have been prepared by a palladium-catalyzed telomerization reaction with butadiene in 2-propanol—water (24). 

The telomerization of sucrose with butadiene was catalyzed in aqueous solution by palladium acetate and tppts (102). The sucrose conversion was about 96%, but octadienyl ethers of different degrees of alkylation were also formed. 

Alkyl ethers of sucrose have been prepared by reaction with long-chain alkyl halides to provide mixtures of regioisomers and products of different degree of substitution.82,83 A similar reaction with chloromethyl ethers of fatty alcohols provides formaldehyde acetals.84,85 Alkenyl ethers of various carbohydrates, and notably of sucrose, can also be obtained by palladium-catalyzed telomerization of butadiene (Scheme 6).86 88 Despite a low-selectivity control, this simple and clean alternative to other reactions can be carried out in aqueous medium when sulfonated phosphines are used as water-soluble ligands. 

K. Hill, B. Gruber, and K. J. Weese, Palladium catalyzed telomerization of butadiene with sucrose A highly efficient approach to novel sucrose ethers, Tetrahedron Lett., 35 (1994) 4541 1542. 

Further work was done in the telomerization of butadiene with carbon dioxide yielding a a-lactone in good yields [116-118]. For the catalyst recycle the successive extraction of the product with 1,2,4-butanetriol was proposed and investigated in detail. Mortreux et al. studied the telomerization of butadiene with sucrose which could also be carried out efficiently in water-organic medium in the presence of Pd salt and TPPTS [119]. Mono- and dioctadienylether were selectively obtained using aqueous sodium hydroxide/isopropanol mixtures. 

Scheme 11 Telomerization of butadiene with sucrose in basic aqueous medium.

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