ISSN:
0170-2041
Keywords:
McMurry reaction
;
Crown ethers
;
Hydroxylation, enantioselective
;
Ion exchange membranes
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A high-yield synthesis of o, o′ crown ether-bridged stilbenes 3b-e by reductive McMurry condensation of (2-formylphenyl)oligoethylene glycols 2b-e with facile (E/Z) diastereomer separation by selective cation complexation is described. Derivatization of the stilbene double bonds of (E)- or (Z)-3b-e affords dihydroxy crown ethers 4c, d and 5c, d diastereo- and enantioselectively. Likewise, trans- and cis-epoxides 11b-d and 12b-d are stereospecifically obtained. A crown ether-bridged diphenylacetaldehyde 13 is formed by rearrangement of 11c or 12c. Photocyclization of 3e yields large-ring 1,8-phenanthrene crown ether 18. The crystal structures of racemic 5c and of 12d are presented. A high caesium selectivity compared to the other alkali metal and alkaline earth cations is found for ion exchange membranes with incorporated crown ether (Z)-3c.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199419941211
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