Browsing by Author "PAREDES, MC"
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- ItemSTUDIES ON QUINONES .18. SYNTHESIS OF DIELS-ALDER ADDUCTS OF ACTIVATED QUINONES WITH (E)-1-TRIMETHYLSILYLOXYBUTA-1,3-DIENE(1989) VALDERRAMA, JA; FARINA, F; PAREDES, MC
- ItemSTUDIES ON QUINONES .24. REARRANGEMENT OF DIELS-ALDER ADDUCTS OF ACTIVATED QUINONES UNDER ACIDIC CONDITIONS(PERGAMON-ELSEVIER SCIENCE LTD, 1992) FARINA, F; PAREDES, MC; VALDERRAMA, JAThe Diets-Alder adducts 5, 19, 9, 10, 8, 11, of benzoquinones bearing activating groups (COCH3, COCH=CHPh, CO2Me, NO2, CHO, CN) by treatment with 1.3 N hydrochloric acid are initially converted into the dihydrobenzofurans 7, 22, the corresponding alcohols 12, 13 or the arylcrotonaldehydes 14, 15, respectively. By treatment with 8.5 N hydrochloric acid, adducts 8-10 are converted directly into the corresponding dihydrobenzofurans. In the presence of silica gel, adduct 19 is partially converted into the benzocyclooctatriene derivative 21. The alcohol 26, formed by hydrolysis of adduct 25, rearranges to the benzodifuran derivatives 28 and 29 in the presence of silica gel and ethanol or methanol, respectively.
- ItemSTUDIES ON QUINONES .28. NOVEL REARRANGEMENTS OF DIELS-ALDER ADDUCTS OF NAPHTHO-DIQUINONES AND ANTHRADIQUINONES(1993) FARINA, F; PAREDES, MC; VALDERRAMA, JAThe Diels-Alder adducts 7a,b by acidic hydrolysis afford the alcohols 8a,b, which in the presence of silica gel, rearrange into the quinizarin derivative 10a and minor amounts of the naphthofuran 11. The rearrangement of 8a,b with silica gel in the presence of ethanol affords the naphthofuran type products 12 and 15. The thermal rearrangement of alcohols 8a,b by heating in benzene solution affords a mixture of the rearranged products 10a,b and the spirocompound 18. Under similar thermal conditions, the alcohol 3 produced the leuconaphthazarin derivative 19 and the spirocompound 20.
- ItemSYMPATHETIC NERVOUS-SYSTEM MEDIATES URINARY KALLIKREIN EXCRETION IN CONSCIOUS RATS(1987) ALBERTINI, R; VARGAS, L; OLIVERI, P; PARDO, F; PAREDES, MC