Medium ring ethers synthesis

Fujiwara K (2006) Total Synthesis of Medium-Ring Ethers from Laurencia Red Algae. 5 ... 

Two step synthesis of medium-ring ethers through the intermediacy of thionium ions followed by sulfide reduction. 

Contemporary Organic Synthesis 1 457 (1994) (Recent Developments in the Synthesis of Medium-Ring Ethers)... 

Crimmins MT, Emmitte KA (1999) Total Synthesis of (+)-Laurencin An Asymmetric Alkylation-Ring-Closing Metathesis Approach to Medium Ring Ethers. Org Lett I 2029... 

The photoisomerization of cyclobutanones to transient car-benes has been used as part of an interesting synthesis of muscarine (Pirrung and DeAmicis). Intramolecular oxetan formation has been used as part of novel syntheses of medium-ring ethers (1) and the tricyclo-octane (2) (Carless et al. Gleiter and Kissler). Cossy et al. have employed the photoreductive cycliza-... 

Synthesis of prelaureatin, laurencin, and the medium-ring ether parts of ciguatoxins 07Y502. 

Preparation of novel lH-1,2,3-, 2H-1,2,3-, lH-1,2,4- and 4H-1,2,4-triazole derivatives A patent review (2008—2011) 13EOT319. Progress (since 2000) in the synthesis of oxepanes and medium ring ethers 12T6999. 

Recent progress in the synthesis of oxepanes and medium ring ethers. Tetrahedron, 68, 6999-7018. (d) Vilotijevic, L, Jamison, T. F. (2009). Epoxide-opening cascades in the synthesis of polycyclic polyether natural products. Angewaudte Cheruie lutematioual Edition, 48, 5250-5281. (e) Snyder, N. L., Haines, H. M., Peczuh, M. W. (2006). Recent developments in the synthesis of oxepines. Tetrahedron, 62, 9301-9320. (f) For medium-ring thiacycles Rosowsky, A. 1972. In Weissberger, A., Taylor, E. C. (Eds.) Heterocyclic Compounds. Wiley, New York. Vol. 26. 

A.S. Kleinke, D. Webb, T.F. Jamison, Recent progress in the synthesis of oxepanes and medium ring ethers. Tetrahedron 68 (2012) 6999-7018. 

Crimmins MT, Emmitte KA, Choy AL. Ring closing metathesis of the formation of medium ring ethers the total synthesis of (—)-isolaurallene. Tetrahedron 2002 58(10) 1817-1834. 

Oishi, T., Shoji, M., Maeda, K., Kumahara, N., and Hirama, M. (1996) Extensive ring-expansion strategy for the enantioselective synthesis of the medium ring ethers, oxepene, oxocane, and oxonene, of ciguatoxin. Synlett, 1165-1167. 

Carling, R.W., Clark, J.S., and Holmes, A.B. (1992) Synthesis of medium ring ethers. Part 2. Synthesis of the firlly saturated carbon skeleton of Laurenda non-terpenoid ether metabolites containing seven-, eight- and nine-membered rings. J. Chem. Soc., Perkin Trans. I, 83-94. 

Crimmins, M.T. and Emmitte, K.A. (1999b) Total synthesis of (-l-)-laurendn an asymmetric alkylation-ring-dosing metathesis approach to medium ring ethers. Org. Lett., 1, 2029-2032. 

C. W. Johannes, M. S. Visser, G. S. Weatherhead, A H. Hoveyda Zr-Catalyzed Kinetic Resolution of Allylic Ethers and Mo-Catalyzed Chromene Formation in Synthesis. Enantioselective Total Synthesis of the Antihypertensive Agent (SJUUD-Nebivolol J. Am Chem Soc 1998, 120, 8340-8347. For development of the enantioselective methodology, see M. S. Visser, J. P. A. Harrity, A. H. Hoveyda Zirconium-Catalyzed Kinetic Resolution of Cyclic Allylic Ethers. An Enantioselective Route to Unsaturated Medium Ring Systems , J. Am Chem Soc 1996,118, 3779-3780. 

The acetal [1,2]-Wittig rearrangement protocol is also applicable to the synthesis of medium-sized cyclic ethers. For example, a reaction of the 9-membered cyclic acetal 37 with lithium piperidide provides the 8-membered ring ether 38 in good yield along with high diastereoselectivity (equation 20) . 

The syntheses of crown compounds invariably rely upon the Williamson ether synthesis, a dated but reliable reaction which is extemely useful in the synthesis of these medium-ring and large-ring compounds.7 The syntheses are usually not discussed in much detail in the literature, since the emphasis in the general area of supramolecular chemistry is on the properties of the target compounds, not on their preparation. It is frequently the case, however, that these apparently conventional syntheses are far from straightforward. 

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