Syntheses of 2, 5‐Dialkylfuran and Tetrahydrofuran Carbinols and Their Cytotoxic Activity

Abstract

2, 5-Dialkylfuran and tetrahydrofuran compounds as structural elements of Annonaceae acetogenins like Asitrocinwere synthesized starting from furfural by Grignard reactions, lithiation of the furan ring and addition of aliphatic aldehydes. Hydrogenation of the furan rings over Pd-catalyst gave the corresponding tetrahydrofurans. All resulting compounds showed no or rather less antimicrobial activity against grampositive, gram-negative bacteria and fungi compared to tetracycline or clotrimazol but high cytotoxic activity against HL 60 cell line determined in the MTT assay.

New Approach towards Cytotoxic Furyl Macrolactones by Ring Closing Metathesis

“…Chemistry Racemic alcohols 2a -c, obtained from furan-2-carbaldehyde by reaction with alkenyl Grignard reagents [2,7] were esterified with undec-10-enoyl chloride to give the esters 3a -c. These esters were converted to the unsaturated macrolactones 4a -c by ring closing metathesis (RCM) using Grubbs catalyst I (Aldrich, Germany) in dichloromethane or toluene [8,9]. Reaction in toluene was much faster than in dichloromethane (Scheme 1).…”

“…The mixture was extracted with diethyl ether (3630 mL) and the combined organic layers were dried over Na 2 (Z)-17-Furan-2-yl-17-hydroxy-2,2-dimethylheptadec-12-en-3-one 6 220 mg (0.7 mmol) of 4c were dissolved in 20 mL dry THF and 1 mL 1.5 M (1.5 mmol) tert.-BuLi in n-hexane were added. The mixture was stirred for 10 h at rt., quenched with 20 mL brine and was extracted with diethyl ether (3630 mL).…”

“…In continuation of our work on cytotoxic furan compounds [1,2] we tried to find out, whether unsaturated furyl macrolactones show cytotoxic activities. Furan and tetrahydrofuran heterocycles are part of numerous natural cytotoxic products like (l)-4-ipomeanol 1a [3], furano-epothilone D 1b [4] (Fig.…”

Synthesis of New Lipophilic Ipomeanol Analogues and Their Cytotoxic Activities

“…1 H-NMR (CDCl 3 ): δ (ppm) ϭ 1.93 (dt, J ϭ 7.5 Hz, J ϭ 7.5 Hz, 2 H, 2-H), 2.17 (dddt, J ϭ 1,3 Hz, J ϭ 7.5 Hz, J ϭ 7.0 Hz, J ϭ 1. (11) (±)-1-(Furan-2-yl)hex-5-en-1-ol (11) was prepared as described in [9]. 2,6-triol (12) 500 mg (3.0 mmol) of 11 were dissolved in 50 mL tert.…”

Design and cytotoxic evaluation of new annonaceous acetogenin analogues

“…In continuation of our work on the synthesis of analogues of annonaceous acetogenin analogues 3 we describe here a new approach towards the acetogenin skeleton. Commercially available 5-iodofuran-2-carbaldehyde (Aldrich) (1) was reacted in a Sonogashira reaction with undec-10-yn-1-ol to give the aldehyde 3.…”