Tetracyclone, conversion into

Section II, A, 3)], by conversion into the mercury compound 102 and subsequent heating. Aryne 98 was trapped with tetracyclone and the product (103) was formed in 70% yield. 

Substrates with electron acceptors are given in Scheme 4. For these rather unreactive n-systems, besides longer reaction times and excess dioxirane, elevated temperature (ca. 25 °C) was essential for complete conversion into their corresponding epoxides. Fortunately, these epoxides, which were all obtained quantitatively, were sufficiently stable for rigorous characterization. The specific substrate types include oc,P-unsaturated acids [20] 21 and esters [20] 22 hydroxychalcones [21] 23 a,P-enones [20] 24 2-cyclohexenones [20] 25 methylene-P-lactones [22] 26 tetracyclone [20] 27 and naphthaquinone [16] 28. The particular advantage of the dioxirane methodology is that labile functional groups, e.g. the phenolic moiety in the chalcones, do not require protection. 

Tetraphenylcyclopentadiene. This useful diene (2) is not easily available, although tetraphenylcyclopentadienone (1, tetracyclone) is prepared readily (1, 1149). An early study1 of conversion of (1) into (2) by reduction was not particularly promising, the best yield (18%) being obtained by inverse lithium... 

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