... Tetrahedron. Volume 69, Issue 1, 7 January 2013, Pages 334–340. ... To a solution of pentenolide 10 (2.28 g, 6.95 mmol, 1 equiv) in MeOH (100 mL) was added H 2 O 2 (35%, 2.13 mL, 24.3 mmol, 3.5 equiv) and 6 N NaOH (0.7 mL, 4.17 mmol, 0.6 equiv) at 0 °C. After 10 min, a ...