%0 Journal Article %A Ruzziconi, Renzo %A Ricci, Giacomo %A Gioiello, Antimo %A Couthon-Gourvès, Hélène %A Gourvès, Jean-Philippe %D 2003 %T First General Approach to Cyclohex-3-ene-1,1-bis(phosphonates) by Diels−Alder Cycloaddition of Tetraethyl Vinylidenebis(phosphonate) to 1,3-Dienes %U https://acs.figshare.com/articles/journal_contribution/First_General_Approach_to_Cyclohex-3-ene-1_1-bis_phosphonates_by_Diels_Alder_Cycloaddition_of_Tetraethyl_Vinylidenebis_phosphonate_to_1_3-Dienes/3694023 %R 10.1021/jo0205154.s002 %2 https://acs.figshare.com/ndownloader/files/5784381 %K diene %K VBP %K tetraethyl %K cycloadduct %K Diel %K Tetraethyl %K reaction times %K First General Approach %K mixture converges %K regioisomeric ratio %X Tetraethyl vinylidenebis(phosphonate) (VBP) reacts smoothly with substituted 1,3-dienes at 90−110 °C without solvent to give the corresponding cyclohex-3-ene-1,1-bis(phosphonates) in good yields (60−85%). With nonsymmetrically substituted dienes, mixtures of regioisomers are obtained, the regioisomeric ratio being exclusively controlled by electronic effects. Danishefsky's diene allows tetraethyl 4-oxocyclohex-2-ene-1,1-bis(phosphonate) to be obtained in an 81% overall yield after the acid-catalyzed hydrolysis of the Diels−Alder cycloadduct. With 2,3-dimethoxy-1,3-butadiene, a mixture of regioisomeric dimethoxycyclohexene-1,1-bis(phosphonates) is formed by the VBP-catalyzed isomerization of the normal Diels−Alder cycloadduct. The mixture converges into tetraethyl 3,4-dimethoxycyclohex-2-ene-1,1-bis(phosphonate) at prolonged reaction times. %I ACS Publications