60 KB223 KB50 KB199820252006Grošelj, UrošMeden, AntonRečnik, SimonStanovnik, BrankoSvete, Jurij12 straništevilka:3letnik:53str. 245-256ISSN:1318-0207COBISSID:27954437URN:URN:NBN:SI:doc-LZCZCGGQenSlovensko kemijsko društvoActa chimica slovenicaderivati pirazolaenaminoniheterociklične spojinekafrakondenzacijaNMR spektroskopijaorganska kemijarentgenska strukturna analizasintezastereoselektivne sintezeSynthesis and transformations of some N-substituted (1R,4S)-3-aminomethylidene-1,7,7-trimethylbicyclo2.2.1-heptan-2-ones|Acid-catalysed reactions of (1R,3E,4S)-3-(dimethylamino)methylidene-1,7,7-trimethylbicyclo2.2.1hept an-2 -one (2) with amino acid derivatives 3a-d and pyrazolidin-3-ones 5a-e gave the substitution products 4/4a-d and 6a-e, respectively, in 40-83% yields. Compound 4a was transformed with Bredereckćs reagent into the 3-(dimethylamino)propenoate 7/7. Treatment of 1-{(1R,3Z,4S)-1,7,7-trimethyl-2-oxobicyclo-2.2.1hept-3-ylide-nemethyl}p yrazolidin-3-ones 6a and 6b with dimethyl acetylenedicarboxylate in refluxing anisole furnished the corresponding cycloadducts as mixtures of four diastereomers, the major endo-isomers 10/11a,b and the minor exo-isomers 12/13a,b with moderate endo-selectivity. Chromatographic separation of 10/11/12/13a,b afforded the endo/exo-pairs of diastereomers, 10/13a,b and 11/12a,b. The structures of compounds 4/4, 6, 7/7, and 10/11/12/13were determined by NMR and by X-ray diffractionPri kislinsko kataliziranih reakcijah (1R,3E,4S)-3-(dimetilamino)metiliden-1,7,7-trimetilbiciklo-2.2.1heptan- 2-on a (2) z .-aminokislinskimi derivati 3a-d in pirazolidin-3-oni 5a-e poteče izmenjava dimetilaminske skupine, ki vodi do nastanka ustreznih N-substituiranih (1R,4S)-3-aminometiliden-1,7,7-trimetilbiciklo2.2.1heptan-2-onov4/4a-d in 6a-e. Izmenjave dimetilaminske skupine z .-aminokislinskimi derivati 3a-d so vodile do zmesi večinskih (3E)-izomerov 4a-d in manjšinskih (3Z)-izomerov 4a-d, medtem ko so bile pretvorbe enaminona 2 s pirazolidinoni 5a-e stereoselektivne saj so nastali izključno ustrezni (3Z)-izomeri 6a-e. Pretvorba spojine 4a z bis(dimetilamino)-terc-butoksimetanom (Bredereckovim reagentom) je vodila do 3-(dimetilamino)propenoata 7/7. Izvedli smo tudi pretvorbi 1-{(1R,3Z,4S)-1,7,7-trimetil-2-oksobiciklo2.2.1hept-3-ilidenmetil}piraz olid in-3-onov 6a and 6b z dimetil acetilendikarboksilatom (DMAD). V obeh primerih sta nastali ustrezni zmesi štirih diastereomernih spojin, 10/11/12/13a in 10/11/12/13b, z večinskima endo-izomeroma 10 in 11 ter manjšinskima ekso-izomeroma 12 in 13. S preparativno tekočinsko kromatografijo (MPLC) smo zmesi štirih izomerov 10/11, 12/13 uspeli ločiti na dva endo/ekso-para izomerov, 10/13 in 11/12. Strukture produktov so bile potrjene z NMR spektroskopijo in z rentgensko strukturno analizoTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaSlovensko kemijsko društvo