Dodecamethyl-cyclohexasilane

The reaction with excess R2(C6H5)SiLi reagents in tetrahydrofuran for a prolonged period of time leads to considerable formation of dodecamethyl-cyclohexasilane, [(CH3)2Si]6, and R2(C6H5)SiSi(C6H5)R2 (see Section III, C, 7). 

These catenated cyclic polysilanes, as well as others such as dodecamethyl-cyclohexasilane, are of special value for several reasons. We have shown that A and B, in particular, can be opened by some metals, halogens, and halogen acids to give compounds of high synthetic value. 

Prepa ation.—Dimethylsilyl enol ethers of aldehydes and ketones may be prepared by irradiating the carbonyl compounds in the presence of dodecamethyl-cyclohexasilane (MeaSije/ Highly stereoselective formylation of (Z)-enol silyl ethers has been achieved on treatment of acyclic ketones with ethyl tri-methylsilylacetate and tetrabutylammonium fluoride on the other hand lithiation of pentan-3-one with lithium 2,2,6,6-tetramethylpiperidide followed by chloro-trimethylsilane gave mainly (84%) the ( )-enol silyl ether... 

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