13C-NMR studies on halomethylvinyl chrysanthemic acids and esters - spin-lattice relaxation time and 13C - 1H coupling constants.

Synthesis of Chloromethylvinylcyclopropanecarboxylic Acid Derivatives

“…After being heated for 30 min at 80 ~ 85°C, the resulting water was distilled azeotropically by adding 200ml of benzene. (6). A solution of 5 (572mg, 2.6mmol) in 150ml of acetic acid was refluxed for 4 hr.…”

“…After cooling, the reaction mixture was separated by column chromatography on silica gel to afford 804 mg of the trans isomer 10, 446 mg of the cis isomer 11, 447 mg of a mixture of 10 and 11 (42 % total yield) and 1. (6) with ethyl diazoacetate. To a stirred solution of 6 (1.54 g, 9.2mmol), powdered copper (20mg) and anhydrous copper(II) su.1fate (40 mg) at 95 ~ 100°C under a nitrogen atmosphere was added slowly dropwise ethyl diazo acetate (395 mg, 3.5 mmol), heating the result for 15 min.…”

“…To a stirred solution of 6 (1.54 g, 9.2mmol), powdered copper (20mg) and anhydrous copper(II) su.1fate (40 mg) at 95 ~ 100°C under a nitrogen atmosphere was added slowly dropwise ethyl diazo acetate (395 mg, 3.5 mmol), heating the result for 15 min. After cooling, the mixture was purified by column chromatography (hexane-ethyl acetate = 9 : I) on silica gel to give 191 mg of 2,4-dimethyl-3-(2-methyl-l-propenyl)-5-ethoxycarbonylfuran (16) in a 25% yield and l.l g of the starting material (6 (12 and 13). A solution of a mixture of 10 and 11 (2.9 g, 12 mmol) and 100 mg of conc.…”

Carbon-13 NMR Spectra of Zeatin and Related Compounds

“…For the assignment of two methyl carbons in compounds 2 and 5, the more deshielded signal was assigned to the one which is trans to the amino group.7) This assignment agrees with the observed long range carbon-proton coupling to the C-2' vinyl proton shown in Table II, in which trans-methyl carbon gives a slightly larger coupling constant. 8 ) Carbon-proton coupling constants of compounds 4, 5 and 6 were obtained from proton-coupled spectra by the gated decoupling technique. 9 ) For determinations of the two and three-bond coupling constants, 2 J and 3 J, spectra of deuterium labelled compounds were used to confirm some of the assignments.…”