Adamantane derivatives trimethylsilyl derivative

The first 1-metalloadamantane (38) has been prepared in 50% yield by the acid catalysed redistribution of silylmethyl substituted cyclohexanes [equation (42)]. A s ies of substituted adamantyl derivatives have been prepared from the chloride by cleava of the appropriate trimethylsilyl derivative [equation (43)]. 1-Adamantyltrichlorosilane has been made by the gas phase interaction of AdCl with SiCla and SiaCle, and derivatives have been prepared, as have a variety for 1,3,5,7-tetrasila-adamantane. ... 

Sasaki, T. Usuki, A. Ohno, M. Synthesis of Adamantane Derivatives 49. Substitution Reaction of 1-Adamantyl Chloride with Some Trimethylsilylated Unsaturated Compounds. J.Org. Chem., 1980 vol. 45, 3559-3564. 

The introduction of the trimethylsilyl chloride trapping technique" led to improved yields in the case of simple aliphatic esters. The initial silylated products are easily isolated and can be converted into the acyloins simply and in high yield. For simple aliphatic esters the yields are in the range 56-92%. Use of trimethylsilyl esters, rather than simple alkyl esters, leads to faster reactions, but lower yields.Substituted esters which have been successfully used in the newer procedure include ethyl 2-ethylhexanoate (83%), ethyl trimethylsilylacetate (90%)," ethyl 3-trimethylsilylpropionate (65%)," ethyl phenylacetate (48%)," ethyl 3-phenylpropionate (79%)" and 2-(2-methoxycarbonylethyl)-2-methyl-l,3-dioxolane derived from levulinic acid (65%)." In the case of ethyl adamantane-l-carboxylate the yield using the newer procedure is reported to be inferior to that using the earlier procedure. 

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