title: Mild and selective deprotection method of acetylated steroids and diterpenes by dibutyltin oxide.
abstract: Dibutyltin oxide (DBTO) was first utilized for the deacetylation of steroid and diterpene esters. The results showed the deprotection of acetylated steroids and diterpenes separately with moderate catalysis dibutyltin oxide in methanol selectively removed part acetyl groups of these substrates, whereas several functional groups of the steroids and diterpenes were retained and neither isomerization nor degradation of these substrates was observed. It seems that the acetyl groups with lower steric hindrance or near carbonyl, alkoxy, or hydroxyl groups can be cleaved by the reaction, whereas the acetyl groups with higher steric hindrance or without carbonyl, alkoxy, or hydroxyl groups neighboring were retained under the same conditions. One of the interesting results obtained was the selective hydrolysis of the 3beta-O-acetyl group in the presence of the 6beta group in 3beta,6beta-Di-O-acetyl-5alpha-hydroxypregn-16-en-20-one. This allows for subsequent introduction of one unit at C-3 and the other unit at C-6. This procedure is useful for the synthesis of a series of closely related isomers of 3beta,5alpha,6beta-trihydroxypregn-16-en-20-one and other widespread polyhydroxysteroids in marine organisms and some terrestrial species.
authors.affiliation: Department of Chemistry, New Drug Research & Development Center, Zhengzhou University, No. 75 Da Xue Road, Zhengzhou 450052, PR China.
authors.forename: Shao-Min
authors.initials: SM
authors.lastname: Wang
authors.forename: Yan-Bing
authors.initials: YB
authors.lastname: Zhang
authors.forename: Hong-Min
authors.initials: HM
authors.lastname: Liu
authors.forename: Guo-Bin
authors.initials: GB
authors.lastname: Yu
authors.forename: Ke-Rang
authors.initials: KR
authors.lastname: Wang
mesh_terms: D000107:Acetylation; D002384:Catalysis; D002855:Chromatography, Thin Layer; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D006868:Hydrolysis; D015394:Molecular Structure; D009947:Organotin Compounds / Q000737:chemistry*; D013256:Steroids / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D004224:Diterpenes; D009947:Organotin Compounds; D013256:Steroids; C031078:dibutyltin oxide