Anhydrous magnesium sulphate

Racemic (E)-5-ethylidene-4-phenyldihydrofuran-2-one (2a), (E)-5-ethylidene-4-(4′ methylphenyl)dihydrofuran-2-one (2b), (E)-5-ethylidene-4-(4′-methoxyphenyl)dihydrofuran-2-one (2c) and (E)-4-(benzo[d][1,′3′]dioxol-5′-yl)-5-ethylidenedihydrofuran-2-one (2d) were synthesized previously by our research team from corresponding aromatic aldehydes [33 (link),34 (link)]. (+)-cis-(4S,5S,6R)-5-(1-Iodoethyl)-4-(4′-methylphenyl)dihydrofuran-2-one (1) was synthesized earlier from (+)-(2R,3E)-4-(4′-methylphenyl)but-3-en-2-ol [35 (link)]. 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, purity ≥ 98%) was purchased form Merck. Sodium chloride, anhydrous magnesium sulphate, hydrochloric acid (35–37%) and organic solvents used for the synthesis and extraction were purchased form Chempur. The chemicals used for the preparation of a growing media were purchased from BTL.

The captan standard was purchased from Dr. Ehrenstorfer (Augsburg, Germany). All reagents were of sufficiently high purity for GC analysis. Acetonitrile, acetone, and petroleum ether were purchased from Honeywell Specialty Chemicals Seelze GmbH (Seelze, Germany). Anhydrous magnesium sulphate, sodium chloride, and tri-sodium citrate dihydrate were from Chempur (Piekary Slaskie, Poland). Sodium citrate dibasic sesquihydrate was purchased from Sigma-Aldrich (Steinheim, Germany). As for the sorbents, PSA was purchased from Supelco (Bellefonte, PA, USA), Al₂O₃, ZrO₂, SiO₂ were from POCH (Gliwice, Poland) and Florisil^® was from Sigma-Aldrich (St. Louis, MO, USA).