CAS 542-28-9 appears in our catalog under these names: delta-Valerolactone, Tetrahydro-2H-pyran-2-one, Tetrahydro–2H–pyran–2–one, delta-Valerolactone, 98%, may contain polymer , delta-Valerolactone, >98.0%(GC). Offered by: TRC, TargetMol, GLPBio, Thermo Scientific (Alfa Aesar), Biosynth. Available pack sizes: 100g, 25g, 5g, 1g, 200mg, 500mg, 100mg, 500g.