2026-04-18T05:09:49Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1645782025-12-05T14:22:03Zcom_2072_1057col_2072_478816col_2072_478917col_2072_478923col_2072_478924

00925njm 22002777a 4500 dc Camps García, Pelayo author Gómez Nadal, Tània author Otermin Esteras, Ane author Font Bardia, Ma. Mercedes author Estarellas, Carolina author Luque Garriga, F. Xavier author 2020-06-06T08:18:06Z 2020-06-06T08:18:06Z 2015-08-20 2020-06-06T08:18:06Z Two domino Diels-Alder adducts were obtained from 3,7-bis(cyclopenta-2,4-dien-1-ylidene)-cis-bicyclo[3.3.0]octane and dimethyl acetylenedicarboxylate or N-methylmaleimide under microwave irradiation. From the first adduct, a C20H24 diene with C2v symmetry was obtained by Zn/AcOH reduction, hydrolysis, oxidative decarboxylation and selective hydrogenation. Photochemical [2+2] cycloaddition of this diene gave a thermally unstable cyclobutane derivative, which reverts to the diene. However, both diene and cyclobutane derivatives could be identified by X-ray diffraction analysis upon irradiation of the diene crystal. New six-membered rings are formed upon transannular addition of bromine or iodine to the diene. The N-type selectivity of the addition was examined by theoretical calculations which revealed the distinct susceptibility of the doubly bonded carbon atoms to the bromine attack. Reaccions químiques Fotoquímica Difusió de raigs X Chemical reactions Photochemistry X-ray scattering Short access to belt compounds with spatially close C=C bonds and their transannular reactions