Synthesis and phytotoxicity of 4,5 functionalized tetrahydrofuran-2-ones

Abstract

Neste trabalho relatamos uma síntese versátil de quatorze γ-lactonas análogas, dentre as quais nove são inéditas, a partir do furfural prontamente disponível. A atividade fitotóxica dos compostos sintetizados foi avaliada in vitro pela influência no crescimento de coleóptilos de trigo. A maior parte das porcentagens de inibição foi pequena e não diferenciou do controle após a terceira diluição (100 μmol L -1). Em geral, as lactonas α,β-insaturadas apresentaram melhor atividade que as saturadas. Os compostos mais ativos a 1000 μmol L -1 apresentaram inibições de 51, 68 e 76%. Os resultados indicam que, independentemente da saturação, a presença do anel γ-lactonônico é importante para a bioatividade, mas a sua presença não implica necessariamente boa potência.In this work we report a versatile synthesis of fourteen γ-lactones all structurally related, nine of which are novel compounds, accomplished from the readily available furfural. The phytotoxic activity of the synthesized compounds was evaluated in vitro by the influence on the growth of wheat coleoptiles. The percentages of inhibition were mostly small and not statistically different from control after the third dilution (100 μmol L -1 ). In general, α,β-unsaturated lactones presented better activities than the saturated ones. The most active compounds presented 51, 68 and 76% of inhibition in 1000 μmol L -1. The results indicate that regardless of saturation, the presence of the γ-lactone moiety is important for the bioactivity, but their presence has no implications with potency.

Toxicity to Diaphania hyalinata, selectivity to non‐target species and phytotoxicity of furanones and phthalide analogues

“…Electron impact (70 eV) mass spectra were recorded using a Shimadzu GC‐MS‐QP5050A. 5‐Hydroxyfuran‐2(5 H )‐one 1 was prepared as previously described …”

“…5‐Isopropyloxyfuran‐2‐( 5H )‐one 3 (507.9 mg, 3.58 mmol) and freshly distilled cyclopentadiene (1.5 mL, 18.38 mmol) were added to a round‐bottom flask (25 mL). The reactants were stirred at room temperature for 96 h, and the excess cyclopentadiene was removed under reduced pressure.…”

Structural elucidation of dioxa‐cage compounds from tetrahydroisobenzofuran‐1(3H)‐one: analysis of NMR data and GIAO chemical shifts calculations

“…Reagents and solvents were obtained from commercial sources and were purified according to standard procedures when necessary . 5‐Hydroxyfuran‐2(5 H )‐one was prepared as previously described . The progress of the reactions was checked by TLC with precoated plates of silica gel .…”

“…[51] 5-Hydroxyfuran-2(5H)-one was prepared as previously described. [52] The progress of the reactions was checked by TLC with precoated plates of silica gel. [53] Column chromatography was carried out on silica gel (60-230 mesh).…”

Isolation and stereochemical assignment of phthalides resulting from the Diels–Alder reaction between 5-isopropoxyfuran-2(5H)-one and cyclopentadiene

“…5-isopropoxyfuran-2(5H)-one 1 was prepared as previous described [33]. Melting points were obtained on an MQAPF-301 melting point apparatus and are uncorrected.…”