Synthesis of Episterol, 5-Dehydroepisterol and Their Deuterio-labeled Analogs

To identify and conduct metabolic studies on sterols in Arabidopsis dwarf mutants, episterol, 5-dehydroepisterol, [26, 27-2H6] 5-dehydroepisterol and [26, 27-2H6] episterol were synthesized from 3 β-acetoxycholest-5-en-24-one or its deuteno-labeled analog by introduction of the 5, 7-diene group, olefination of the 24-oxo group with Tebbe reagent and reduction of 5, 7-diene with sodium as key reactions.