Highly Regio- and Stereoselective Cyclic Iodoetherification of 4,5-Alkadienols. An Efficient Preparation of 2-(1′(Z)-Iodoalkenyl)tetrahydrofurans

• Published in: Journal of organic chemistry Vol. 74; no. 1; pp. 438 - 441
• Main Authors: Lü, Bo, Jiang, Xinpeng, Fu, Chunling, Ma, Shengming
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 02.01.2009; Amer Chemical Soc
• Subjects: Alcohols - chemistry; Chemistry; Chemistry, Organic; Cyclization; Exact sciences and technology; Furans - chemical synthesis; Furans - chemistry; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Iodine - chemistry; Molecular Conformation; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; Stereoisomerism; OXIDATION; DIASTEREOSELECTIVE SYNTHESIS; CATALYZED REACTIONS; TETRAHYDROFURAN DERIVATIVES; RING; 2,3-ALLENOATES; ALDEHYDES; SULFONES; ALLENES; CYCLIZATION; Acetylenic compound; Regioselectivity; Furan derivatives; Propargylic compound; Alcohol; Dienic compound; Oxygen heterocycle; Etherification; Diastereoselectivity; Chemical coupling; Stereoselectivity; Sonogashira coupling; Iodination; Cyclic compound; Optical resolution; Chirality; Chlorocarbon; Dichloromethane; Chemical synthesis; Allenic compound; Room temperature; Electrophile; Iodine
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo802079b

In this paper, an efficient way to synthesize 2-(1′(Z)-iodoalkenyl)tetrahydrofurans from 4,5-alkadienols and I2 was developed. The reaction of the 4,5-allenols with a substituent in the 3-position afforded the trans-2,3-disubstituted tetrahydrofurans with very high diastereoselectivity. However, when the axially optically active 4,5-allenol was treated with I2 in n-hexane, the efficiency for chirality transfer was low. This problem was circumvented by conducting the reaction in CH2Cl2 at room temperature and applying N-iodosuccinimide as the electrophilic reagent; however, the Z/E ratio for the products is much lower. Highly optically active Z-products may be prepared via the kinetic resolution via a Sonogashira coupling reaction with propargyl alcohol.