d5-Reactions of Doubly Deprotonated ?,?-Unsaturated Carbonyl Derivatives with Electrophiles. A Novel Approach to the Synthesis of Tetrahydrofuran and Tetrahydropyran Derivatives
作者:Dieter Seebach、Manat Pohmakotr、Christian Schregenberger、Beat Weidmann、Raghao S. Mali、Srisuke Pohmakotr
DOI:10.1002/hlca.19820650202
日期:1982.3.17
tested (alkyl halide, silyl chloride, ester, ketone, aldehyde, epoxide) to give β, γ-unsaturated carbonyl compounds of type A (see Formulae2–6, 13, 14 and Tables 1–5). The α- and β-hydroxyalkylation products obtained from 1a–1d can be converted to tetra-hydrofuran and tetrahydropyran derivatives 7 and 16, respectively (Tables 1 and 2), those from the sulfur analogues 1e and 1f to ketene thioacetals
SEEBACH, D.;POHMAKOTR, M.;SCHREGENBERGER, C.;WELDMANN, B.;MALI, R. S.;POH+, HELV. CHIM. ACTA, 1982, 65, N 2, 419-450
作者:SEEBACH, D.、POHMAKOTR, M.、SCHREGENBERGER, C.、WELDMANN, B.、MALI, R. S.、POH+
DOI:——
日期:——
POHMAKOTR M.; SEEBACH D., ANGEW. CHEM. <ANCE-AD>, 1977, 89, NO 5, 333-334
作者:POHMAKOTR M.、 SEEBACH D.
DOI:——
日期:——
Syntheses of Substituted 6-Hydroxyhexenoic Acids and Related Tetrahydrofuran Systems by Metallocene-Template Directed 1,4-Selective Coupling of 1,3-Butadiene with Carbonyl Compounds
作者:Gerhard Erker、Martin Berlekamp、Luis Lopez、Matthias Grehl、Bruno Schönecker、Reimar Krieg
DOI:10.1055/s-1994-25441
日期:——
Butadiene is 1,4-selectively coupled with a metal carbonyl and a ketone at the bis(η-cyclopentadienyl)zirconium template to yield the nine-membered metallacyclic products 3. Subsequent hydrolysis under oxidative conditions (pyridine N-oxide) gives the corresponding substituted 6-hydroxy-3-hexenoic acids 5. By this procedure a -CH2CH=CHCH2CO2H nucleophile has thus formally been added to the ketone substrate. Esterification of 5 followed by treatment with a base converts these organic template coupling products into substituted tetrahydrofuran acetic acids. Similarly, ketones are linearly coupled with butadiene and a nitrile to yield analogously structured hydroxyalkenones 15 which undergo acid catalyzed ring closure to yield the -CH2COR substituted tetrahydrofurans 16.