Allene-yne-enes

In toluene, an intramolecular [2+2+2] cyclization of allene-yne-enes was performed to produce tricyclic compounds [106] [Eq. (45)]. 

A ruthenium(II)-catalysed intramolecular [2 + 2 -i- 2] cyclization of allene-yne-enes has been reported to proceed via a ruthenacyclopentene intermediate formed from the allene-yne or ene-yne moiety to give tricyclic compounds stereospecifically (Scheme 158).2°4... 

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See also in sourсe #XX -- [ ]

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