CAS 6089-09-4 appears in our catalog under these names: 4-Pentynoic acid, 4-Pentynoic acid, 95% , 4-Pentynoic acid, 95%, 4-Pentynoic acid 98%, 4-Pentynoic acid, 98.38%. Offered by: Fluorochem, Thermo Scientific (Alfa Aesar), Thermo Scientific (Acros), Ambeed, Sigma-Aldrich. Available pack sizes: 1g, 5g, 10g, 25g, 100g, 500g, 1 g, 50 g.