4866-55-1

Basic information

• Product Name: 1α,2α-Dimethyl-3-methylenecyclopropane
• Synonyms: (1S,2R)-1,2-Dimethyl-3-methylenecyclopropane
• CAS NO: 4866-55-1
• Molecular Formula: C6H10
• Molecular Weight: 82.14
• Mol File: 4866-55-1.mol
• Article Data: 1

Chemical Properties

• Boiling Point: 56.0±7.0 °C(Predicted)
• Appearance: /
• Density: 0.78±0.1 g/cm3(Predicted)
• CAS DataBase Reference: 1α,2α-Dimethyl-3-methylenecyclopropane(CAS DataBase Reference)
• NIST Chemistry Reference: 1α,2α-Dimethyl-3-methylenecyclopropane(4866-55-1)
• EPA Substance Registry System: 1α,2α-Dimethyl-3-methylenecyclopropane(4866-55-1)

Safety Data

• Hazardous Substances Data: 4866-55-1(Hazardous Substances Data)

Upstream product

• 31501-95-8 cis-methylenecyclopropane-2,3-dicarboxylic anhydride 
• 5070-00-8 (-)-trans-2,3-dimethylmethylenecyclopropane 
• 590-18-1 (Z)-2-Butene 
• 75-25-2 Bromoform 
• 74-88-4 methyl iodide 
• 4866-55-1 (-)(2S,3S)-trans-2,3-Dimethylmethylencyclopropan 
• 57476-07-0 (Z)-2,3-bis(hydroxymethyl)-1-methylenecyclopropane 
• 75-34-3 1,1-dichloroethane 

Downstream Products

• 123482-31-5 CH(CH₃)CH(CH₃)CHCH₂OH 
• 1569-59-1 3-methylpent-4-en-2-ol 
• 23038-04-2 2-cis-3-trans-Dimethyl-cyclopropyl-methanol 

Relevant articles and documents

CROSS-CONJUGATED BIRADICALS. KINETICS AND KINETIC ISOTOPE EFFECTS IN THE THERMAL ISOMERIZATIONS OF CIS- AND TRANS-2,3-DIMETHYLMETHYLENECYCLOPROPANE, CIS- AND TRANS-3,4-DIMETHYL-1,2-DIMETHYLENECYCLOBUTANE, AND OF 1,2,8,9-DECATETRAENE

cis- and trans-2,3-Dimethylmethylenecyclopropane (C and T) interconvert at 160.0o with a small normal kinetic isotope effect (KIE) when the exo-methylene is deuterated, but the 1,3-shift products, 2-methylethylidenecyclopropane, show a large normal KIE, 1.35 and 1.31, when formed from C and T, respectively.This data can be interpreted in terms of either parallel reactions or a common trimethylenemethane diradical intermediate formed with a normal KIE of 1.11 and closing to 1,3-shift product with a normal KIE of 1.29 due to the effect of deuterium in the required 90o rotation of the exo-methylene carbon.The kinetics of the thermal 1,3- and 3,3-shifts of cis- and trans-3,4-dimethyl-1,2-dimethylenecyclobutane (CB and TB) were determined in a flow reactor.The first order rate constants are log kCB (sec-1) = 13.7-42,200/2.3 RT and log kTB (sec-1) = 13.6-41,900/2.3 RT (Ea in kcal/m) which compare favorably to that from the parent hydrocarbon, 1,2-dimethylenecyclobutane, after reasonable correction for dimethyl substitution.Rearrangement of TB and its bis(dideuteriomethylene) derivative at 230.0o revealed a normal KIE of 1.08.This KIE could be interpreted in terms of either a methylene rotational isotope effect in a concerted reaction or formation of a bisallyl diradical with the expected normal rotational IE on closure to the 1,3-shift product of 1.12 with no IE in the ring opening when the result is corrected for return of the biradical to starting material.The kinetics of intramolecular 2 + 2 cycloaddition of 1,2,8,9-decatetraene were determined in a flow reactor.The first order rate constant is log k(sec-1) = 9.4-30,800/2.3 RT (Ea in kcal/m).These energetics are compared with those of other 2 + 2 cycloadditions.The major product is 3,4-dimethylenecyclooctene (DC) which is also formed from the minor product, cis-7,8-dimethylenebicyclooctane (CO), at higher temperatures.The trans isomer, TO, also gives DC at about the same rate as CO.