SYNTHESES AND PROPERTIES OF ETHINYLATED AND TRIMETHYLSILYLETHINYLATED MOLECULAR-SYSTEMS WITH THE 1,6-METHANO[10]ANNULENE FRAGMENT

2-Trimethylsilylethinylated 1,6-methano[10]annulene 1 a was obtained by reaction of 2-bromo-1,6-methano[10]annulene with trimethylsilylacetylene in the presence of bis-(triphenylphosphin-)-Pd (II) chloride and Cu(I) and also by reaction of 1,1-diiodo-2-(1,6-methano[10]annulene-2-yl)-ethene (2) with n-buthyl-lithium followed by hydrolysis. 1 a reacts with 2N NaOH to 2-ethinyl-1,6-methano[10]annulene (1 b). 2,7- and 2, 10-dibromo-1,6-methano[10]annulene can be substituted to give the trimethylsilylethinylated compounds 3 a-6 a, which then can be transformed with 2N NaOH into the desilylated products 3 b-5 b.