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【结 构 式】 
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【分子编号】15589 【品名】ethyl 2-hydroxycyclohexanecarboxylate; Ethyl cis-2-hydroxy-1-cyclohexanecarboxylate 【CA登记号】6149-52-6 |
【 分 子 式 】C9H16O3 【 分 子 量 】172.22424 【元素组成】C 62.77% H 9.36% O 27.87% |
合成路线1
该中间体在本合成路线中的序号：(XXX)7) The potassium salt (XIV), immediate precursor of sanfetrinem cilexetil can also be obtained as an enantiomeric mixture by the following sequence: The reduction of 2-oxocyclohexanecarboxylic acid ethyl ester (XXIX) with H2 over PtO2 in ethanol gives a mixture of the cis- and trans-2-hydroxycyclohexane (XXX), which is separated by distillation and treated with tert-butyldimethylsilyl chloride and imidazole in THF to yield cis-2-(tert-butyldimethylsilyloxy)cyclohexanecarboxylic acid ethyl ester (XXXI) as an enantiomeric mixture cis-(S,R)/cis-(R,S) (for the sake of clarity only one of the enantiomers is presented). The reduction of (XXXI) with diisobutylaluminum hydride (DIBAL) in ether affords the corresponding aldehyde (XXXII), which is treated with lithium trimethylsilylamide in THF to give the silylated imine (XXXIII). The cyclization of (XXXIII) with lithium tert-butyl acetate (XXXIV) in THF yields the silylated azetidinone (XXXV), which is deprotected by treatment with tetrabutylammonium fluoride (TBAF) in THF affording the hydroxyazetidinone (XXXVI). The reaction of (XXXVI) with 2,2-dimethoxypropane (XXXVII) and BF3 ethearate in dichloromethane gives the acetonide (XXXVIII), which is condensed with acetyltrimethylsilane (XXXIX) by means of lithium diisopropylamide (LDA) and potassium tert-butoxide (in order to introduce the 1-hydroxyethyl group) yielding the alkylated acetonide (XL). The trimethylsilyl protection of (XL) was removed and substituted with a more stable tert-butyldimethylsilyl (TBS) group affording (XLI), which is treated with pyridine chlorochromate (PCC) to give the previously reported 2-oxocyclohexylazetidinone (XVII) (Scheme 2), but as an enantiomeric mixture. The reaction sequence was continued (XVII) -> (XVIII) -> (XIX) -> (VIII) as in Scheme 2, and (VIII) -> (IX) -> (X) -> (XI) -> potassium salt (XIV) (all the compounds as enantiomeric mixtures). Note that if the starting compound is 2-oxocyclohexane-1(S)-carboxylic acid ethyl ester, instead of the racemic compound (XXIX), the potassium salt (XIV) can be obtained in enantiomerically pure form.
| 【1】 Camerini, R.; Panunzio, M.; Bonanomi, G.; Donati, D.; Perboni, A.; Highly stereocontrolled synthesis of a novel tribactam by reaction of an ester enolate with a N-trimethylsilylimine. Tetrahedron Lett 1996, 37, 14, 2467-70. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (VIII) | 15566 | (3S,4R)-3-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-4-[(1R,3S)-3-methoxy-2-oxocyclohexyl]-2-azetanone | C18H33NO4Si | 详情 | 详情 | |
| (IX) | 15567 | benzyl 2-[(2R,3S)-3-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-2-[(1R,3S)-3-methoxy-2-oxocyclohexyl]-4-oxoazetidinyl]-2-oxoacetate | C27H39NO7Si | 详情 | 详情 | |
| (X) | 15568 | benzyl (1S,5S,8aS,8bR)-1-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-5-methoxy-2-oxo-1,2,5,6,7,8,8a,8b-octahydroazeto[2,1-a]isoindole-4-carboxylate | C27H39NO5Si | 详情 | 详情 | |
| (XI) | 15569 | benzyl (1S,5S,8aS,8bR)-1-[(1R)-1-hydroxyethyl]-5-methoxy-2-oxo-1,2,5,6,7,8,8a,8b-octahydroazeto[2,1-a]isoindole-4-carboxylate | C21H25NO5 | 详情 | 详情 | |
| (XIV) | 15572 | potassium (1S,5S,8aS,8bR)-1-[(1R)-1-hydroxyethyl]-5-methoxy-2-oxo-1,2,5,6,7,8,8a,8b-octahydroazeto[2,1-a]isoindole-4-carboxylate | C14H18KNO5 | 详情 | 详情 | |
| (XVII) | 15575 | (3S,4R)-3-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-4-[(1R)-2-oxocyclohexyl]-2-azetanone | C17H31NO3Si | 详情 | 详情 | |
| (XVIII) | 15576 | (3S,4R)-3-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-4-[(1S)-2-cyclohexen-1-yl]-2-azetanone | C17H31NO2Si | 详情 | 详情 | |
| (XIX) | 15577 | (3S,4R)-3-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-4-[(1S,2R,6R)-7-oxabicyclo[4.1.0]hept-2-yl]-2-azetidinone | C17H31NO3Si | 详情 | 详情 | |
| (XXIX) | 11889 | ethyl 2-oxocyclohexanecarboxylate; Ethyl 2-cyclohexanonecarboxylate | 1655-07-8 | C9H14O3 | 详情 | 详情 |
| (XXX) | 15589 | ethyl 2-hydroxycyclohexanecarboxylate; Ethyl cis-2-hydroxy-1-cyclohexanecarboxylate | 6149-52-6 | C9H16O3 | 详情 | 详情 |
| (XXXI) | 15590 | ethyl (1S,2R)-2-[[tert-butyl(dimethyl)silyl]oxy]cyclohexanecarboxylate | C15H30O3Si | 详情 | 详情 | |
| (XXXII) | 15591 | (1S,2R)-2-[[tert-butyl(dimethyl)silyl]oxy]cyclohexanecarbaldehyde | C13H26O2Si | 详情 | 详情 | |
| (XXXIII) | 15592 | N-[(E)-((1R,2R)-2-[[tert-butyl(dimethyl)silyl]oxy]cyclohexyl)methylidene](trimethyl)silanamine; N-[(E)-((1R,2R)-2-[[tert-butyl(dimethyl)silyl]oxy]cyclohexyl)methylidene]-N-(trimethylsilyl)amine | C16H35NOSi2 | 详情 | 详情 | |
| (XXXIV) | 15593 | [2-(tert-butoxy)-2-oxoethyl]lithium | C6H11LiO2 | 详情 | 详情 | |
| (XXXV) | 15594 | (4S)-4-((1R,2R)-2-[[tert-butyl(dimethyl)silyl]oxy]cyclohexyl)-2-azetanone | C15H29NO2Si | 详情 | 详情 | |
| (XXXVI) | 15595 | (4S)-4-[(1R,2R)-2-hydroxycyclohexyl]-2-azetanone | C9H15NO2 | 详情 | 详情 | |
| (XXXVII) | 10722 | 1-Methoxy-1-methylethyl methyl ether; 2,2-Dimethoxypropane | 77-76-9 | C5H12O2 | 详情 | 详情 |
| (XXXVIII) | 15597 | (5aR,9aR,9bS)-4,4-dimethyloctahydro-2H-azeto[1,2-c][1,3]benzoxazin-2-one | C12H19NO2 | 详情 | 详情 | |
| (XXXIX) | 15598 | 1-(trimethylsilyl)-1-ethanone | 13411-48-8 | C5H12OSi | 详情 | 详情 |
| (XL) | 15599 | (1R,5aR,9aR,9bR)-4,4-dimethyl-1-[(1R)-1-methyl-2-(trimethylsilyl)ethyl]octahydro-2H-azeto[1,2-c][1,3]benzoxazin-2-one | C18H33NO2Si | 详情 | 详情 | |
| (XLI) | 15600 | (1S,5aR,9aR,9bR)-1-((1R)-1-[[tert-butyl(dimethyl)silyl]oxy]ethyl)-4,4-dimethyloctahydro-2H-azeto[1,2-c][1,3]benzoxazin-2-one | C20H37NO3Si | 详情 | 详情 |
合成路线2
该中间体在本合成路线中的序号：(XLIII)Several alternative routes to the intermediate amine (V) are shown in Scheme 4. The asymmetric reduction of ethyl 2-oxocyclohexanecarboxylate (XLII) gives the (1R,2S)-hydroxy ester (XLIII), which is converted to amide (XLIV) by treatment with aqueous ammonia and ammonium chloride. After activation of the hydroxyl group of (XLIV) as the corresponding mesylate (XLV), displacement with the potassium alkoxide of 3,4-dimethoxyphenethyl alcohol (XI) affords the trans-amide ether (XLVI). The target amine (V) is then obtained by Hofmann rearrangement of carboxamide (XLVI) employing NaOCl and NaOH. A different resolution method involves transesterification of ethyl 2-oxocyclohexanecarboxylate (XLII) with benzyl alcohol, followed by enzymatic reduction of the resulting benzyl keto ester (XLVII) with carbonyl reductase to provide the (1R,2R)-hydroxy ester (XLVIII). Coupling of (XLVIII) with imidate (X) furnishes the benzyl phenethoxycyclohexanecarboxylate (XLIX), which is subjected to benzyl group hydrogenolysis to provide acid (L). This compound can also be obtained by condensation of ethyl 2(R)-hydroxy-1(R)-cyclohexanecarboxylate (LI) with 3,4-dimethoxyphenethyl trichloroacetimidate (X), followed by alkaline hydrolysis of the obtained ethyl 2-phenethoxycyclohexanecarboxylate (LII). Optionally, the ethyl ester (LII) can be converted to amide (XLVI) by reaction with methanolic ammonia, or to hydrazide (LIII) by treatment with hydrazine hydrate in EtOH. Conversion of acid (L) to the target amine (V) can then be accomplished by Curtius rearrangement employing diphenylphosphoryl azide. Analogously, diazotization of hydrazide (LIII), followed by Curtius rearrangement of the intermediate acyl azide and alkaline hydrolysis results in the target amine (V) (2). Scheme 4.
| 【2】 Plouvier, B.M.C., Chou, D.T.H., Jung, G. et al. (Cardiome Pharma Corp.). Synthetic process for aminocyclohexyl ether compounds. WO 2006088525. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (V) | 65266 | (1R,2R)-2-[2-(3,4-dimethoxyphenyl)ethoxy]cyclohexylamine | C16H25NO3 | 详情 | 详情 | |
| (X) | 65272 | 3,4-dimethoxyphenethyl trichloroacetimidate | C12H14Cl3NO3 | 详情 | 详情 | |
| (XI) | 38711 | 2-(3,4-dimethoxyphenyl)-1-ethanol | 7417-21-2 | C10H14O3 | 详情 | 详情 |
| (XLII) | 11889 | ethyl 2-oxocyclohexanecarboxylate; Ethyl 2-cyclohexanonecarboxylate | 1655-07-8 | C9H14O3 | 详情 | 详情 |
| (XLIII) | 15589 | ethyl 2-hydroxycyclohexanecarboxylate; Ethyl cis-2-hydroxy-1-cyclohexanecarboxylate | 6149-52-6 | C9H16O3 | 详情 | 详情 |
| (XLIV) | 65300 | cis-2-Hydroxy-1-Cyclohexanecarboxamide; (1R,2S)-2-Hydroxy-1-Cyclohexanecarboxamide; Zinc01081409 | 73045-98-4 | C7H13NO2 | 详情 | 详情 |
| (XLV) | 65301 | C7H12NaNO2 | 详情 | 详情 | ||
| (XLVI) | 65302 | C17H25NO4 | 详情 | 详情 | ||
| (XLVII) | 65303 | C14H16O3 | 详情 | 详情 | ||
| (XLVIII) | 65304 | C14H18O3 | 详情 | 详情 | ||
| (XLIX) | 65305 | C24H30O5 | 详情 | 详情 | ||
| (L) | 65306 | C16H24O5 | 详情 | 详情 | ||
| (LI) | 65307 | Ethyl trans-2-hydroxycyclohexanecarboxylate | 3444-72-2 | C9H16O3 | 详情 | 详情 |
| (LII) | 65308 | C19H28O5 | 详情 | 详情 | ||
| (LIII) | 65309 | C17H26N2O4 | 详情 | 详情 |