Allylic oxidation of ent-Kaurenic acid, ent-Kaurenic acid Methyl Ester and ent-Kaurenol

Avances en Química

关键词: Allylic oxidation;    selenium oxide;    hydrogen peroxide;    ent-kaurenic acid;    ent-kaurenic acid methyl ester;    ent-kaurenol;   

DOI  :  

来源: DOAJ

【 摘 要 】

The allylic oxidation of ent-kaurenic acid, ent-kaurenic acid methyl ester, and ent-kaurenol with SeO2/H2O2 is presented. The reaction was run in dioxan solution at room temperature stirring for 4 hours. About 0.3 mmol of substrate was treated with 1.2 mmol of SeO2 and 4.1 mmol of H2O2. Treatment of ent-kaurenic acid afforded 56% of ent-15α- hydroxy-kaur-16-en-19-oic acid (2a). Treatment of ent-kaurenic acid methyl ester afforded two products: ent-15α-hydroxy-kaur-16-en-19-oic acid methyl ester (2b, 34% yield) and ent-15α,16α-epoxi-17-hydroxy- kauran-19-oic acid methyl ester (3a, 59% yield). In a similar fashion treatment of ent-kaurenol rendered two products: ent-15α,17- dihydroxy-kaur-16-ene (2c, 56.7% yield) and ent-15α,16α-epoxi-17,19- dihydroxy-kaurane (3b, 34% yield). Additional experiments using twice as much or half as much H2O2 relative to the amount of SeO2 did not modify significantly the product ratio neither the yield.

【 授权许可】

Unknown