[1,3]Dipolar cycloaddtion of 2-diazopropane on 2,6-dibenzylidenecyclohexanone 2 done at 0°C lead to tow bis-spiro-Δ1-pyrazolines: diastereoisomers 3 and 4. The same addition reaction carried out at -50°C gave in addition to adducts 3 and 4 and for the first time a new spiro-Δ3-(1,3,4)oxadiazoline with an inverse regiochemical way. The pyrolysis of 3 and 4 gave the ethylenic derivatives 6 and 7.
N. Boukamcha, M.T. Martin , A. Khemiss
2-diazopropane, bis-spiro-Δ1-pyrazolines, spiro-Δ3-(1,3,4)oxadiazoline