Other a-Substituted Alkylstannanes

Alternatively, the a-alkoxyalkyltin compounds can be formed from an R3SnLi or R3SnMgX reagent and an alkoxyalkyl halide. A convenient one-pot process is shown in equation 6-8.27 

The normal protic Pummerer rearrangement has its metallic equivalent in the stannyl (and silyl) Pummerer reaction,46 9 for example 47 

Me3SnOMe + N2 Me0H (Me3Sn)2CN2 180 °c Me3SnN=C=NSnMe3 Me02CCsCC02Me 

The only example of the equivalent of a Corey-Seebach reaction of the lithium derivative of a carbonyl-protected aldehyde involves an acetylenic ketone (equation 6-25).61 

An alternative approach is to treat hexamethylditin with an acyl halide in the presence of a Pd(0) or Pd(II) catalyst, but the reaction is not successful with higher hexaalkyl-distannanes.62 

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