Nitroalkenes as dienophiles

Dienophiles substituted with appropriate heteroatoms may offer a number of advantages such as (1) provide dienophilic equivalents of C-—C and moieties which do not undergo [4 + 2] cycloadditions to 1,3-dienes because of low (e.g. isolated alkenes, alkynes, allenes) or different reactivities (e.g. ketenes) (2) enhance or invert the regiochemistry of the Diels-Alder process (3) permit facile removal of the activating and/or regiocontrolling group after cycloaddition with or without introduction of further functionalities. The use of nitroalkenes as dienophiles demonstrates these issues most strikingly. [Pg.320]

Diels-Alder reaction with nitroalkenes as dienophiles. The B(OAc)3-promoted Diels-Alder reaction of juglone (76) with substituted styrenes (77) in the presence of DDQ produced cycloadducts (78). This methodology provides a route to the total synthesis of tetrangulol (79) and anhydrolandomycinone (80) (Scheme 24) ... [Pg.451]

See also in sourсe #XX -- [ Pg.231 , Pg.232 , Pg.233 , Pg.234 , Pg.235 , Pg.236 , Pg.237 , Pg.238 , Pg.239 , Pg.240 , Pg.241 , Pg.242 , Pg.243 , Pg.353 ]

See also in sourсe #XX -- [ Pg.342 ]

See also in sourсe #XX -- [ Pg.907 ]

See also in sourсe #XX -- [ Pg.907 ]

See also in sourсe #XX -- [ Pg.907 ]

See also in sourсe #XX -- [ Pg.342 ]

See also in sourсe #XX -- [ Pg.292 ]

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