Experimental evidence of a cyclopropylcarbinyl conjugative electronic effect.
Bicyclo[3.2.0]hept-2-enes undergo thermal rearrangement to norbornenes via diradical transition structures. The synthesis of exo-7-cyclopropylbicyclo[3.2.0]hept-2-ene has been achieved by cycloaddition of cyclopentadiene and cyclopropylketene, generated by treatment of cyclopropylacetyl chloride with triethylamine. A comparison of the cyclopropyl substituent effect with that of other C7 substituents provides experimental evidence of an electron-donating conjugative effect on the transient diradical transition structure in the thermal reaction of exo-7-cyclopropylbicyclo[3.2.0]hept-2-ene.
Department of Chemistry, Franklin & Marshall College, Lancaster, PA, USA. phyllis.leber@fandm.edu
Phyllis A
PA
Leber
Anthony J
AJ
Nocket
Matthew F
MF
Wipperman
Sylvia
S
Zohrabian
Christopher Y
CY
Bemis
Munsha K
MK
Sidhu
D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D004583:Electrons; D015394:Molecular Structure
D001643:Bridged Bicyclo Compounds; D003521:Cyclopropanes