{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,22]],"date-time":"2025-10-22T02:52:36Z","timestamp":1761101556543},"reference-count":15,"publisher":"Elsevier BV","issue":"50","license":[{"start":{"date-parts":[[2000,12,1]],"date-time":"2000-12-01T00:00:00Z","timestamp":975628800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Tetrahedron Letters"],"published-print":{"date-parts":[[2000,12]]},"DOI":"10.1016\/s0040-4039(00)01782-2","type":"journal-article","created":{"date-parts":[[2002,7,25]],"date-time":"2002-07-25T20:58:46Z","timestamp":1027630726000},"page":"9835-9838","source":"Crossref","is-referenced-by-count":20,"title":["A novel synthesis of arcyriaflavin-A via an intramolecular sulfur extrusion reaction"],"prefix":"10.1016","volume":"41","author":[{"given":"M.Manuel","family":"B. Marques","sequence":"first","affiliation":[]},{"given":"Maria M.M","family":"Santos","sequence":"additional","affiliation":[]},{"given":"Ana M","family":"Lobo*","sequence":"additional","affiliation":[]},{"given":"Sundaresan","family":"Prabhakar","sequence":"additional","affiliation":[]}],"member":"78","reference":[{"key":"10.1016\/S0040-4039(00)01782-2_BIB1","doi-asserted-by":"crossref","first-page":"29","DOI":"10.2174\/0929867306666220207210053","volume":"6","author":"Pindur","year":"1999","journal-title":"Curr. Med. Chem."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB2","doi-asserted-by":"crossref","unstructured":"Gribble, G. W.; Berthel, S. J. In Studies in Natural Products Chemistry; Atta-ur-Rahman, Ed.; Elsevier Science: Amsterdam, 1993; Vol. 12, pp. 365\u2013409.","DOI":"10.1016\/B978-0-444-89366-6.70015-0"},{"key":"10.1016\/S0040-4039(00)01782-2_BIB3","doi-asserted-by":"crossref","first-page":"2689","DOI":"10.1016\/0040-4039(95)00363-H","volume":"36","author":"Fonseca","year":"1995","journal-title":"Tetrahedron Lett."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB4","unstructured":"This work was presented in the 19th European Colloquium on Heterocyclic Chemistry held in Aveiro (Portugal) July 19\u201322, 2000."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB5","doi-asserted-by":"crossref","first-page":"5279","DOI":"10.1016\/S0040-4039(00)77084-5","volume":"35","author":"Bergman","year":"1994","journal-title":"Tetrahedron Lett."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB6","unstructured":"The dithiete 4 (200 mg) in dry DMF (4 ml), under an argon atmosphere, was treated with n-Bu3P (186 \u03bcl) at 0\u00b0C. On completion of the reaction (ca. 10 min; TLC control), dibromomaleimide (173 mg) in dry DMF (4 ml) was added dropwise and the resulting mixture, protected from light, was kept at 0\u20136\u00b0C (3 days). It was then diluted with EtOAc, washed repeatedly with water, and dried (Na2SO4). Evaporation of the solvent furnished a red residue which on purification by column chromatography (SiO2; n-hexane\/ethyl ether, 2:8) afforded biindolyl (38 mg) and the bis-sulfide 3 (124 mg, 47%; 59% based on recovered biindolyl). Selected data for 3: 1H NMR (acetone-d6) \u03b4 7.27 (2H, t, J 7.3 Hz), 7.34 (2H, t, J 7.6 Hz), 7.59 (2H, d, J 8 Hz), 7.76 (2H, d, J 8 Hz), 10.08 (1H, s, exchangeable in D2O), 11.49 (2H, exchangeable in D2O); IR (KBr) \u03bdmax 3337 (br), 1775, 1720 cm\u22121. HRMS, M+ (found) 389.0305. C20H11N3O2S2 requires 389.0293."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB7","doi-asserted-by":"crossref","first-page":"3795","DOI":"10.1016\/S0040-4039(99)00529-8","volume":"40","author":"Marques","year":"1999","journal-title":"Tetrahedron Lett."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB8","unstructured":"Method A\u2014Compound 3 (38.3 mg) and 1,2,2,6,6-pentamethylpiperidine (17 \u03bcl) in o-dichlorobenzene (15 ml) was heated under an argon blanket, in an oil bath (2.5 h, 150\u00b0C). The solution at room temperature was diluted with ethyl acetate washed with dil. HCl (1N), then with water and dried (Na2SO4). Evaporation of the solvent under reduced pressure furnished a red residue which was crystallised from EtOAc\u2013n-hexane to afford arcyriaflavin-A (19 mg). Purification of the residue from the mother-liquor by ptlc provided an additional quantity of 1 (2.8 mg). Method B\u2014A toluene solution (14 ml) of 3 (50 mg) and 1,2,2,6,6-pentamethylpiperidine (46 \u03bcl) was refluxed under argon (13 h). The precipitate that formed on cooling the reaction mixture to 0\u00b0C was collected by decantion, suspended in EtOAc and stirred with dil. HCl (1N). The organic phase was washed with water and dried (Na2SO4). Evaporation of the solvent furnished a red solid (30 mg, 72% yield) which was found to be identical in all respects (TLC, 1H NMR, IR) with a sample of arcyriaflavin-A.3 A further quantity of virtually pure 1 (7.8 mg, 18%) could be secured by concentrating the original toluene solution to half its bulk and processing the precipitate obtained as above. The reaction in the absence of the base was found to take more than 2 days for completion."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB9","doi-asserted-by":"crossref","first-page":"710","DOI":"10.1002\/hlca.19710540229","volume":"54","author":"Roth","year":"1971","journal-title":"Helv. Chim. Acta"},{"key":"10.1016\/S0040-4039(00)01782-2_BIB10","doi-asserted-by":"crossref","unstructured":"Shiosaki, K. In Comprehensive Organic Synthesis; Trost, B. M.; Fleming, I., Eds.; Pergamon Press: Oxford, 1991; Vol. 2, pp. 865\u2013892.","DOI":"10.1016\/B978-0-08-052349-1.00051-2"},{"key":"10.1016\/S0040-4039(00)01782-2_BIB11","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1002\/anie.197407362","volume":"13","author":"Vogel","year":"1974","journal-title":"Angew. Chem. Int. Ed."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB12","doi-asserted-by":"crossref","first-page":"6332","DOI":"10.1021\/ja01120a531","volume":"75","author":"Scott","year":"1953","journal-title":"J. Am. Chem. Soc."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB13","doi-asserted-by":"crossref","first-page":"8361","DOI":"10.1016\/S0040-4039(00)61431-4","volume":"34","author":"Harris","year":"1993","journal-title":"Tetrahedron Lett."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB14","doi-asserted-by":"crossref","first-page":"5555","DOI":"10.1016\/S0040-4039(00)77245-5","volume":"35","author":"Xie","year":"1994","journal-title":"Tetrahedron Lett."},{"key":"10.1016\/S0040-4039(00)01782-2_BIB15","unstructured":"NOTE ADDED IN PROOF: In a very recent paper Schr\u00f6th's group (cf. Schr\u00f6th, W.; Spitzner, R.; Felicetti, M.; Wagner, C.; Bruhn, C. Eur. J. Org. Chem. 2000, 3093, Ref. 26 cited therein) questioned structure 4, assigned5 to the material derived from 2,2\u2032-bisindole and elemental sulfur. Instead it was suggested that it is dimer 5,6,17,18-tetrahydro[1,2,7,8]tetrathiacyclodecino[4,3-b:5,6-b\u2032:10,9-b\u2032\u2032:11,12-b\u2032\u2032\u2032]tetraindole. If it were to be true, then it is assumed that this substance can generate 6 and 4 in situ on reaction with n-Bu3P in DMF."}],"container-title":["Tetrahedron Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0040403900017822?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0040403900017822?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2023,4,13]],"date-time":"2023-04-13T13:29:20Z","timestamp":1681392560000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S0040403900017822"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2000,12]]},"references-count":15,"journal-issue":{"issue":"50","published-print":{"date-parts":[[2000,12]]}},"alternative-id":["S0040403900017822"],"URL":"https:\/\/doi.org\/10.1016\/s0040-4039(00)01782-2","relation":{},"ISSN":["0040-4039"],"issn-type":[{"value":"0040-4039","type":"print"}],"subject":[],"published":{"date-parts":[[2000,12]]}}}