3-NITRO-2-PHENYL-2-TRIFLUOROMETHYL-2<i>H</i>-CHROMENES IN REACTIONS WITH AZOMETHINE YLIDES FROM ISATINS AND (THIA)PROLINE: SYNTHESIS OF SPIRO[CHROMENO(THIA)PYRROLIZIDINE-11,3'-OXINDOLES]
Authors
Игорь Б. Кутяшев
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
Иван A. Кочнев
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
Анастатсия A. Черепкова
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
Николай C. Зимницкий
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
Алексей Ю. Барков
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
Владислав Ю. Коротаев
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
Вячеслав Я. Сосновских
Institute of Natural Sciences and Mathematics of Ural Federal University
named after the first President of Russia B. N. Yeltsin,
51 Lenina Ave., Yekaterinburg 620000, Russia
1,3-Dipolar cycloaddition of stabilized azomethine ylides generated in situ from isatins and proline to 3-nitro-2-phenyl-2-trifluoromethyl-2H-chromenes in i-PrOH proceeds stereoselectively at room temperature and leads to the formation of hexahydro-6H-spiro[chromeno[3,4-a]pyrrolizine-11,3'-indolin]-2'-ones with the cis arrangement of the trifluoromethyl group and the nitro group. A similar reaction with the participation of thiaproline-based ylides at 50°С leads to mixtures of diastereomeric tetrahydro-6H,9H-spiro[chromeno[3',4':3,4]pyrrolo[1,2-c]thiazole-11,3'-indolin]-2'-ones with a predominance of the cis- or trans-isomer. The stereochemistry of the obtained products was confirmed by the NOESY experiment and X-ray structural analysis.
