{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T08:31:27Z","timestamp":1777451487808,"version":"3.51.4"},"reference-count":36,"publisher":"Wiley","issue":"13","license":[{"start":{"date-parts":[[2007,1,19]],"date-time":"2007-01-19T00:00:00Z","timestamp":1169164800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemistry A European J"],"published-print":{"date-parts":[[2007,4,27]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Reactions of salicylaldehydes with ethyl buta\u20102,3\u2010dienoate or penta\u20103,4\u2010dien\u20102\u2010one catalyzed by a catalytic amount of potassium carbonate produce the corresponding 2\u2009<jats:italic>H<\/jats:italic>\u2010chromene products in moderate to good yields under mild conditions. A plausible reaction mechanism is discussed in the light of the results of an <jats:sup>18<\/jats:sup>O\u2010labeling experiment. In addition, in view of these findings, the catalytic function of DBU in reactions of this kind is reconsidered.<\/jats:p>","DOI":"10.1002\/chem.200601033","type":"journal-article","created":{"date-parts":[[2007,1,19]],"date-time":"2007-01-19T04:48:21Z","timestamp":1169182101000},"page":"3701-3706","source":"Crossref","is-referenced-by-count":61,"title":["A Facile Synthetic Route to 2\u2009<i>H<\/i>\u2010Chromenes: Reconsideration of the Mechanism of the DBU\u2010Catalyzed Reaction between Salicylic Aldehydes and Ethyl 2\u2010Methylbuta\u20102,3\u2010dienoate"],"prefix":"10.1002","volume":"13","author":[{"given":"Lun\u2010Zhi","family":"Dai","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yong\u2010Ling","family":"Shi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gui\u2010Ling","family":"Zhao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Min","family":"Shi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2007,4,19]]},"reference":[{"key":"e_1_2_5_1_2","unstructured":"\u00a0"},{"key":"e_1_2_5_2_2","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1002\/9780470187012.ch2","volume-title":"Chromenes, Chromanes, Chromones","author":"Schweizer E. E.","year":"1977"},{"key":"e_1_2_5_3_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.986685"},{"key":"e_1_2_5_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/B978-008096519-2.00046-1"},{"key":"e_1_2_5_5_2","unstructured":"\u00a0"},{"key":"e_1_2_5_6_2","doi-asserted-by":"publisher","DOI":"10.1002\/adsc.200404239"},{"key":"e_1_2_5_7_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200502913"},{"key":"e_1_2_5_7_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200502913"},{"key":"e_1_2_5_8_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200352154"},{"key":"e_1_2_5_8_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200352154"},{"key":"e_1_2_5_9_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200501485"},{"key":"e_1_2_5_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol051920v"},{"key":"e_1_2_5_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol051044l"},{"key":"e_1_2_5_12_2","doi-asserted-by":"publisher","DOI":"10.1002\/adsc.200505496"},{"key":"e_1_2_5_13_2","unstructured":"CCDC\u2010283692 contains the supplementary crystallographic data for compound3\u2009b. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk\/data_request\/cif. Empirical formula: C14H16O5; formula weight: 264.27; crystal size: 0.506\u00d70.279\u00d70.237; crystal color habit: colorless prismatic; crystal system: triclinic; lattice type: primitive; lattice parameters:a= 8.5461(11) b= 8.9372(4) c= 11.0662(14)\u2005\u00c5 \u03b1= 111.524(2) \u03b2= 92.403(3) \u03b3= 117.794(2)o V= 671.86(15)\u2005\u00c53; space group:P$\\bar 1$;Z= 2;\u03c1calcd= 1.306\u2005g\u2009cm\u22123;F000= 280;R1 = 0.0477 wR2 = 0.1138. Diffractometer: Rigaku AFC7\u2009R."},{"key":"e_1_2_5_14_2","unstructured":"For reactions of allenoates with aldehydes catalyzed by phosphine Lewis bases see:"},{"key":"e_1_2_5_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol050203y"},{"key":"e_1_2_5_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol050946j"},{"key":"e_1_2_5_17_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja0344009"},{"key":"e_1_2_5_18_2","unstructured":"\u00a0"},{"key":"e_1_2_5_19_2","doi-asserted-by":"publisher","DOI":"10.1039\/b414895a"},{"key":"e_1_2_5_20_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo0490907"},{"key":"e_1_2_5_21_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.19780900806"},{"key":"e_1_2_5_21_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.197805691"},{"key":"e_1_2_5_22_2","unstructured":"For DBU acting as a base see:"},{"key":"e_1_2_5_23_2","doi-asserted-by":"publisher","DOI":"10.1002\/adsc.200404318"},{"key":"e_1_2_5_24_2","first-page":"1779","author":"Tewari N.","year":"2002","journal-title":"Synlett"},{"key":"e_1_2_5_25_2","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1055\/s-2001-13421","author":"Reddy N. S.","year":"2001","journal-title":"Synlett"},{"key":"e_1_2_5_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo0008791"},{"key":"e_1_2_5_27_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo971417z"},{"key":"e_1_2_5_28_2","unstructured":"For other examples of the synthesis of chromenes see:"},{"key":"e_1_2_5_29_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja981142k"},{"key":"e_1_2_5_30_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja048078t"},{"key":"e_1_2_5_31_2","first-page":"1243","author":"Mondal M.","year":"2004","journal-title":"Synlett"},{"key":"e_1_2_5_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tetlet.2004.07.158"},{"key":"e_1_2_5_33_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol047578o"}],"container-title":["Chemistry \u2013 A European Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchem.200601033","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chem.200601033","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T16:00:35Z","timestamp":1760284835000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/chem.200601033"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,4,19]]},"references-count":36,"journal-issue":{"issue":"13","published-print":{"date-parts":[[2007,4,27]]}},"alternative-id":["10.1002\/chem.200601033"],"URL":"https:\/\/doi.org\/10.1002\/chem.200601033","archive":["Portico"],"relation":{},"ISSN":["0947-6539","1521-3765"],"issn-type":[{"value":"0947-6539","type":"print"},{"value":"1521-3765","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,4,19]]}}}