Cyclo-1,2-dienes (C-9-C-13) are converted into the synthetically promi
sing 2,3-bis(trimethylsilyl)- and 2,3-bis(trimethylstannyl)cycloalk-1-
enes by disilylation with lithium chlorotrimethylsilane in tetrahydrof
uran, and Pd-0-catalysed addition of hexaalkyldistannes, respectively.