27567-69-7

Upstream product

• 463-49-0 1,2-propanediene 
• 513-81-5 2,3-dimethyl-buta-1,3-diene 
• 74-95-3 1,1-dibromomethane 

Downstream Products

• 72525-22-5 tricyclo<10.4.0.0^4,9>hexadeca-1(12),4(9)-diene-6,7:14,15-bis(N-phenyldicarboximide) 

Relevant academic research and scientific papers

Reactions of 2,3-Dimethylenebutadiene Dianion with Electrophiles. Synthesis and Conformations of 2,3-Disubstituted-1,3-butadienes

Reactions of 2,3-dimethylenebutadiene dianion 1 with monofunctional electrophiles were found to provide the best routes to symmetrically substituted 1,3-butadienes such as 2c - n.Evidence that at least some of these reactions go by single electron-transfer mechanisms is presented.Possible mechanisms for the formation of some unusual byproducts are discussed.Reactions of 1 with dichlorides and dibromides were found to provide the best routes to most 1,2-dimethylenecycloalkanes 3, the corresponding dimers 4 and trimers 5, and 1,1-dimethyl-3,4-dimethylene-1-metallacyclopentanes 26.From their UV spectra, the dienes 2 contain about 60percent transoid conformations, except 2,3-dimethyl-1,3-butadiene (2a) which shows about 100percent and 2,3-dineopentyl-1,3-butadiene (2h) which shows about 30percent. 1,2-Dimethylenecycloalkanes 3 display cisoid conformations in rings smaller than 9-membered and transoid conformations in rings larger than 11.When the ring size exceeds 15, the homoallylic methylene groups on both sides are also anti coplanar.With rings larger than about 30, the next methylene group on each side is also anti coplanar, and when the ring size exceeds about 45, an additional methylene on each side is anti coplanar.

Alkynes and Cumulenes XXI. - On Some New Oligomers of Allene

The thermal oligomerization of allene (1) in the gas-phase has been reinvestigated.At 260 deg C and low conversion, 1,6,7-trimethylenespirononane (14) and 1,2,5,6-tetramethylenecyclooctane (15) have been detected besides the already known thermal oligomers 2-8.Increase of substrate concentration and reaction time lead to significant amounts of a hexamer fraction which contains the new allene oligomers 16-23 according to spectroscopic analysis.Possible routes of formation of the unusual hexamers 16 and 20 are discussed.