|
【结 构 式】 
|
【分子编号】35287 【品名】[(6aS,6bR,8aR,10S,12aR,12bR)-10-[[tert-butyl(dimethyl)silyl]oxy]-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b-hexadecahydro-4(2H)-picenyl]methanol 【CA登记号】 |
【 分 子 式 】C36H62O2Si 【 分 子 量 】554.97258 【元素组成】C 77.91% H 11.26% O 5.77% Si 5.06% |
合成路线1
该中间体在本合成路线中的序号：(XVIII)Elimination of the benzoyl group of (XV) with DIBAL in dichloromethane affords alcohol (XVI), which is silylated with TBDMS-Cl and imidazole in DMF giving the silyl ether (XVII). Cleavage of the cyclopropane ring of (XVII) with tert-butyl perbenzoate, followed by hydrolysis of the resulting ester yields the methanol derivative (XVIII), which is selectively reduced with Li in THF/NH3 affor-ding the cis-isomer (XIX). Finally, this compound is oxidized with NaClO4 in tert-butanol and desilylated with tetrabutylammonium fluoride.
| 【1】 Huang, A.X.; Corey, E.J.; Xiong, Z.; An exceptionally short and simple enantioselective total synthesis of pentacyclic triterpenes of the beta-amyrin family. J Am Chem Soc 1999, 121, 43, 9999. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (XV) | 35284 | C37H52O2 | 详情 | 详情 | ||
| (XVI) | 35285 | C30H48O | 详情 | 详情 | ||
| (XVII) | 35286 | C36H62OSi | 详情 | 详情 | ||
| (XVIII) | 35287 | [(6aS,6bR,8aR,10S,12aR,12bR)-10-[[tert-butyl(dimethyl)silyl]oxy]-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b-hexadecahydro-4(2H)-picenyl]methanol | C36H62O2Si | 详情 | 详情 | |
| (XIX) | 35288 | [(6aS,6bR,8aR,10S,12aR,12bR,14bS)-10-[[tert-butyl(dimethyl)silyl]oxy]-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b,13,14b-octadecahydro-4(2H)-picenyl]methanol | C36H64O2Si | 详情 | 详情 |
合成路线2
该中间体在本合成路线中的序号：(XX)The cyclization of (XIV) by means of MeAlCl2 in dichloromethane followed by benzoylation with benzoyl chloride gives a mixture of benzoates (XV) and (XVI) that are separated by chromatography. The desired isomer (XV) (additional (XV) is obtained by isomerization of (XVI) by HCl in hot acetic acid) was selctively methylenated with CH2I2 and Br2Zn in toluene yielding the cyclopropanated compound (XVII). Elimination of the benzoyl group of (XVII) with DIBAL in dichloromethane affords alcohol (XVIII), which is silylated with TBDMS-Cl and imidazole in DMF giving the silyl ether (XIX). The cleavage of the cyclopropane ring of (XIX) with tert-butyl perbenzoate, followed by hydrolysis of the resulting ester yields the methanol derivative (XX), which is selectively reduced with Li in THF/NH3 affording the cis-isomer (XXI). Finally, this compound is oxidized with NaClO4 in tert-butanol, and desilylated with tetrabutylammonium fluoride to give the target oleanolic acid.
| 【1】 Corey, E.J.; Lee, J.; Enantioselective total synthesis of oleanolic acid, erythrodiol, beta-amyrin, and other pentacyclic triterpenes from a common intermediate. J Am Chem Soc 1993, 115, 8873. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (XIV) | 35735 | (3S)-3-[(3E,7E)-3,7-dimethyl-10-(2,7,7-trimethyl-3,4,5,6,7,8-hexahydro-1-naphthalenyl)-3,7-decadienyl]-2,2-dimethyloxirane | C29H46O | 详情 | 详情 | |
| (XV) | 35283 | (3S,4aR,6aR,6bS,14aR,14bR)-4,4,6a,6b,11,11,14b-heptamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,9,10,11,12,14,14a,14b-octadecahydro-3-picenyl benzoate | C36H50O2 | 详情 | 详情 | |
| (XVI) | 35736 | (3S,4aR,6aR,6bS,14aR,14bR)-4,4,6a,6b,11,11,14b-heptamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,10,11,12,13,14,14a,14b-octadecahydro-3-picenyl benzoate | C36H50O2 | 详情 | 详情 | |
| (XVII) | 35284 | C37H52O2 | 详情 | 详情 | ||
| (XVIII) | 35285 | C30H48O | 详情 | 详情 | ||
| (XIX) | 35286 | C36H62OSi | 详情 | 详情 | ||
| (XX) | 35287 | [(6aS,6bR,8aR,10S,12aR,12bR)-10-[[tert-butyl(dimethyl)silyl]oxy]-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b-hexadecahydro-4(2H)-picenyl]methanol | C36H62O2Si | 详情 | 详情 | |
| (XXI) | 35288 | [(6aS,6bR,8aR,10S,12aR,12bR,14bS)-10-[[tert-butyl(dimethyl)silyl]oxy]-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b,13,14b-octadecahydro-4(2H)-picenyl]methanol | C36H64O2Si | 详情 | 详情 |