4-Acetoxy-2-alkenylquinolines, analogs of the quinolinol antibiotic SF2420B (1), were synthesized. A previous study found that the 4-acetate of SF2420B (intermediate 2) exhibited high insecticidal activity, leading to the synthesis of SF2420B analogs with modified side chains. Starting materials (5, 6, 9) were prepared via selenium oxide oxidation and phosphonium salt formation. Analogs (13, 14, 16, 18, 11, 12, 15, 17) were synthesized using reactions including Wittig, deprotection, acetylation, and vinylaluminum addition. Insecticidal activity was evaluated on Bombyx mori larvae (topical application) and three pest species (Plutella xylostella, Laodelphax striatellus, Tetranychus urticae; leaf spray). Results showed SF2420B (1) had weak activity (40 μg, 20% mortality), but acetylation (compound 2) enhanced activity (2.5 μg, 100% mortality). Acetylated analogs (11, 12, 15, 17) showed higher activity than non-acetylated ones, with 11 and 12 being the most active. Compound 12 displayed potent activity against P. xylostella (100% at 250 ppm) and moderate activity against L. striatellus (94% at 500 ppm) and T. urticae (100% at 500 ppm).