Preparation and Reactions of Dialkoxytetrahydrofurans²

Studies on the polymerization of bifunctional monomers. XVII. Cyclopolymerization of malealdehyde and the structure of the polymer

“…Table 2 summarizes the NMR chemical shifts of t-e isomers o DADF isolated in the present investigation. As already mentioned with DMDF, one of the isomers, of which chemical shifts of the methine proton appeared a t a higher field than that of the other, was assigned to be cis, 5 taking into account the magnetic anisotropy of the double bond. The migration of the olefin proton peak of the cis isomer to a lower field in benzene can be explained by assuming the formation of a "loose complex" between the cis isomer and a benzene molecule3).…”

Catalysis of Intramolecular Morita–Baylis–Hillman and Rauhut–Currier Reactions by Fluorous Phosphines; Facile Recovery by Liquid/Solid Organic/Fluorous Biphase Protocols Involving Precipitation, Teflon® Tape, and Gore‐Rastex® Fiber

“…A flask was charged with a solution of a dialdehyde (n = 2, succinaldehyde; [26] 3, glutaraldehyde [27] ) in CH 2 Cl 2 (40.0 mL, 0.300 M, 12.0 mmol) and cooled to 0 8C. Then the ylide Ph 3 PCHA C H T U N G T R E N N U N G (C=O)R (5.80 mmol) dissolved in CH 2 Cl 2 (10 mL) was added dropwise with stirring.…”

“…A round-bottom flask was charged with a solution of succinaldehyde [26] in CH 2 Cl 2 (17.0 mL, 0.300 M, 5.20 mmol). Then Ph 3 PCHA C H T U N G T R E N N U N G (C=O)S-i-Pr (4.16 g, 11.0 mmol) dissolved in CH 2 Cl 2 (5 mL) was added with stirring.…”

A new and high yielding synthesis of unstable pyrroles via a modified Clauson-Kaas reaction

“…7 As we wished to avoid the use of strong acids, we investigated the use of aqueous acetic acid. The use of acetic acid would also mean that after hydrolysis sodium acetate could be added to generate a buffer of $pH 5 for the pyrrole formation.…”