Expedient Syntheses of β-Iodofurans by 5-endo-dig Cyclisations

• Published in: European Journal of Organic Chemistry Vol. 2007; no. 34; pp. 5759 - 5770
• Main Authors: Bew, Sean P., El-Taeb, Gamila M. M., Jones, Simon, Knight, David W., Tan, Wen-Fei
• Format: Book Review Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2007; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; Chemistry, Organic; Cyclisation; Furans; Iodocyclisation; Physical Sciences; Science & Technology; ELECTROPHILIC CYCLIZATION; 2-(1-ALKYNYL)-2-ALKEN-1-ONES; ACETYLENE; furans; cyclisation; ALKYNES; DERIVATIVES; SALTS; INTRAMOLECULAR ADDITION; iodocyclisation
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.200700681

5‐endo‐dig cyclisations of 3‐alkyne‐1,2‐diols using iodine as the electrophile proceed smoothly to deliver excellent yields of the corresponding β‐iodofurans. The necessary precursors are available from a number of different approaches, notably regioselective bis‐hydroxylation of conjugated enynes and the addition of acetylides to α‐hydroxy carbonyl groups. The initial iodofurans can be homologated using a number of strategies, ranging from various transition metal‐catalysed couplings to halogen–metal exchange and subsequent coupling with an electrophile. Hence, this method overall represents a flexible, relatively brief and very efficient approach to a variety of highly substituted furans. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)