Triethyl orthoacetate

Acryloyl chloride, bis(cyclopentadienyl)titanium dichloride, 9-borabicyclo[3.3.1]nonane, 3-buten-3-ol, n-butyl acrylate, n-decan-1-ol, Dess-Martin periodinane, diethyl ether, diethylaluminium chloride, n-heptan-1-ol, 6-hepten-1-ol, 1,4-hexadiene, (E)-2-hexen-1-ol, (E)-3-hexen-1-ol, (E)-4-hexen-1-ol, 5-hexen-1-ol, 1-hexen-3-ol, 5-hexyn-1-ol, hydrogen peroxide solution, lithium diisopropylamide, magnesium sulfate, n-octan-1-ol, 1-octen-3-one, n-pentan-1-ol, 4-penten-1-ol, petroleum ether, phenoxyacetic acid, propionic acid, sodium bicarbonate, sodium thiosulfate pentahydrate, tetrahydrofuran, triethyl orthoacetate, trimethylamine, and vinylmagnesium bromide solution were purchased from Sigma-Aldrich (Steinheim, Germany). The educts 1-hepten-3-ol, 1-hexen-3-one, and 7-octen-1-ol were purchased from abcr (Karlsruhe, Germany) and chloroform, sodium hydroxide, and sulphuric acid from Carl Roth (Karlsruhe, Germany). Dichloromethane, ethyl acetate, n-hexyl acrylate, methanol, 1-nonen-3-one, n-propyl acrylate, silica gel (Normasil 60, 40–63 µm), and sodium chloride were purchased from VWR International GmbH (Darmstadt, Germany). All reactants were at least of reagent grade.

Chalcone (purity 97%), triethyl orthoacetate (97%), sodium borohydride (99%), and N-bromosuccinimide (NBS, ≥ 95%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Other chemicals were of analytical grade (Chempur, Piekary Śląskie, Poland). Silica gel for column chromatography (Kieselgel 60, 230–400 mesh) was purchased from (Merck, Darmstadt, Germany).

All experiments were carried out in an atmosphere of dry argon and flasks were flame dried. Solvents were dried by usual methods (diphenyl ether, diethyl ether and THF over benzophenone ketyl, CHCl₃ and CH₂Cl₂ over P₄O₁₀, hexane over sodium-potassium alloy) and distilled. Chromatographic purification was carried out on silica gel 60 (0.15–0.3 mm, Macherey-Nagel GmbH & Co. KG, Düren, Germany). Sodium hydride (dry, 95%), trimethyl orthoformate, triethyl orthoformate, triethyl orthoacetate, trimethyl orthoacetate, 1,10-phenanthroline (4n), 1,10-phenanthrolin-5-amine (5l), 9H-carbazole, pyrrolidine, 10H-phenothiazine, Meldrum’s acid, benzene-1,2-diamine, 4-fluorobenzene-1,2-diamine, 4-chlorobenzene-1,2-diamine, 4-bromobenzene-1,2-diamine, 4-methylbenzene-1,2-diamine, 3,4-diaminobenzonitrile and 3,4-diaminobenzoic acid were purchased from Sigma–Aldrich (Poznan, Poland), and were used without further purification.