A simple and efficient approach to the synthesis of endo and exo bicyclo[6.1.0]nona-3,5-diene-9-carboxaldehyde.
Monobromination of 1,5-cyclooctadiene, followed by cyclopropanation with ethyl diazoacetate, led to the formation of endo and exo ethyl 4,5-dibromobicyclo[6.1.0]nonane-9-carboxylates 3a and 3b. Bis-dehydrobromination of 3a and 3b using 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) afforded the endo and exo ethyl bicyclo[6.1.0]nona-3,5-diene-9-carboxylates 4a and 4b. Reduction of these compounds to the corresponding alcohols 5a and 5b and subsequent oxidation with pyridinium chlorochromate (PCC) resulted in the formation of the target compounds endo and exo bicyclo[6.1.0]nona-3,5-diene-9-carboxaldehydes 6a and 6b.
Ghandi
Mehdi
M
School of Chemistry, University College of Science, University of Tehran, Tehran, Iran. ghandi@khayam.ut.ac.ir
Mashayekhi
Gholamreza
G
D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000737:chemistry*; D001965:Bromides / Q000138:chemical synthesis / Q000737:chemistry; D003521:Cyclopropanes / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure
D019086:Bridged Bicyclo Compounds, Heterocyclic; D001965:Bromides; D003521:Cyclopropanes; C030797:cyclopropane