Trivinyl-methanes

The light-induced rearrangement reactions of trivinyl methanes to give divinyl cyclopropane and vinyl cyclopentene derivatives are known as the tri-n-methane rearrangements. The reaction involves both singlet and triplet excited states. For... 

Another way to circumvent the stereoselectivity issues that may arise from olefination or addition/elimination sequences to l,4-dien-3-ones is to switch the polarity of components and olefinate a carbonyl compound with a symmetrical nucleophilic pentadienyl anion equivalent. A seminal contribution was reported by Paul and Tchelitcheff in 1951, who combined trivinylmethane (235) and carbon dioxide to form a [3]dendralene 237 (Scheme 1.40 (a)) [190]. In this instance, the anion of trivinyl methane 236 is indeed a pentadienyl anion, but bond formation occurs with allylic transposition through a vinyl unit. 

Tris(dimethylsilyl)methane HC(SiMejH)3 was prepared according to the literature procedure. [12] 2,4,6-Trivinyl-2,4,6-trimethyl-cyclotrisiloxane was synthesized nsing Takiguchi method. [13] The cyclosiloxane monomers were kept melted over CaH for several days in an ampoule equipped with a teflon stopcock, and distilled (separately) under vacuum into the polymerization apparatus. All solvents were carefnUy dried according to literature procedures [14] and distilled prior to then-use. Other reagents were used as received. 

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