A series of highly conducting lithium siloxyaluminate polymers containing ethylene oxide side chains were prepared. Conductivities of the order of 10 -5 S cm -1 at 25°C were obtained. The materials were shown to be predominantly Li + ion conductors.

Solvent-free polymer electrolytes are currently under intense scrutiny for use in high-energy density batteries and other electrochemical devices.1 11*'2 In the most common polymer electrolytes, i.e., polymer-salt complexes, high anion transport numbers and low conductivity result in cell polarization and low power density. In addition, the mobility of both ions complicates the investigation of transport mechanisms. For these reasons, our group and others3-13 have investigated polyelectrolytes such as modified poly(phosphazene) with covalently bound anions14'15 and poly(tetraalkoxyaluminate).16 These polyelectrolytes ensure unity transport number for the cation. However, results from these investigations and others indicate that ion pairing limits the performance of these materials.17 To address this issue, our group has explored the use of sequestering agents (cryptands)15'18 and the use of very weakly basic anions attached to the polymer to reduce contact ion pairing. Aluminosilicates are attractive as low-basicity anions that can be incorporated into a polymer by siloxy linkages. In the present research, we prepared several alkoxy aluminosilicate polyelectrolytes to examine the

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Samarium(i1) di-iodide, which is a strong one-electron transfer reducing agent, is effective for the reductive coupling of E,P-unsaturated esters with carbonyl compounds, whereby substituted y-lactones can easily be prepared in good to excellent yields under very mild conditions. Two mole equiv. of samarium(ii) di-iodide to each mole equiv. of starting substrate always give reasonable yields. The presence of an alcohol is essential in the reaction, complex unidentified products being formed in the absence of an alcohol; t-butyl alcohol gave more satisfactory results than methanol and ethanol. The alcohol acts as a proton donor, the use of MeOD leading to a deuteriated y-lactone. The reaction is applicable t o both aliphatic and aromatic ketones or aldehydes, whereas the electrochemical method is limited to aliphatic substrates. The diastereoselectivity is examined in the reaction of 4-tbutylcyclohexanone with ethyl acrylate; an anti-isomer is produced predominantly (syn:anti = 1 : 9) as the result of selective axial attack. The reaction may proceed b y a radical mechanism, and reaction may not involve a samarium ester homoenolate. The reaction is extended to the intramolecular reaction of an ~, punsaturated keto ester (8-oxonon-2-enoate) leading to the ready synthesis of a bicyclic y-lactone. * cis: trans = ca. 75125. cis: trans = ca. 65: 35.14 cis: trans = ca. 70: 30.14 8 Hex-5-en-2-one (lo), 70 * The carbon bearing one deuterium should, in principle, appear as a triplet, It was not, however, observed since the concentration of the sample is low (5-10%) and the peak may be concealed in the noise.

Polymer electrolytes incorporating boroxine rings with pendant oligoether side chains and a variety of dissolved lithium salts were prepared. High ionic conductivities and Li+ transference numbers were observed, the latter being ascribed to the anion trapping ability of the boroxine ring.