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【结 构 式】 
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【分子编号】42624 【品名】(2S)-3-[[tert-butyl(dimethyl)silyl]oxy]-2-methylpropanal 【CA登记号】 |
【 分 子 式 】C10H22O2Si 【 分 子 量 】202.36898 【元素组成】C 59.35% H 10.96% O 15.81% Si 13.88% |
合成路线1
该中间体在本合成路线中的序号：(XIII)The intermediate (XXI) has been obtained as follows: The condensation of the chiral benzylated hydroxypentanone (XII) with the chiral aldehyde (XIII) by means of DCHBCl gives the chiral hydroxyheptanone (XIV), which is protected at the OH group with p-methoxybenzyl trichloroacetimidate (Pmb-Tca), yielding the expected benzyl ether (XV). The reduction of the CO group of (XV) by means of LiAlH4, with simultaneous debenzylation affords the alpha-diol (XVI), which is oxidized with NaIO4 to provide the aldehyde (XVII). The condensation of (XVII) with the allyl compound (XVIII) by means of CrCl2 and KH in THF gives the octadiene compound (XIX), which is desilylated with camphorsulfonic acid (CSA) to yield the unsaturated alcohol (XX). Finally, this alcohol is oxidized with DMP to the desired intermediate aldehyde (XXI).
| 【1】 Paterson, I.; Florence, G.J.; Synthesis of (+)-discodermolide and analogues by control of asymmetric induction in aldol reactions of gamma-chiral (Z)-enals. Tetrahedron Lett 2000, 41, 35, 6935. |
| 【2】 Paterson, I.; et al.; Total synthesis of the antimicrotubule agent (+)-discodermolide using boron-mediated aldol reactions of chiral ketones. Angew Chem. Int Ed Engl 2000, 39, 2, 377. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (XII) | 42623 | (1S)-1-methyl-2-oxobutyl benzoate | C12H14O3 | 详情 | 详情 | |
| (XIII) | 42624 | (2S)-3-[[tert-butyl(dimethyl)silyl]oxy]-2-methylpropanal | C10H22O2Si | 详情 | 详情 | |
| (XIV) | 42625 | (1S,3R,4R,5S)-6-[[tert-butyl(dimethyl)silyl]oxy]-4-hydroxy-1,3,5-trimethyl-2-oxohexyl benzoate | C22H36O5Si | 详情 | 详情 | |
| (XV) | 42626 | (1S,3R,4R,5S)-6-[[tert-butyl(dimethyl)silyl]oxy]-4-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohexyl benzoate | C30H44O6Si | 详情 | 详情 | |
| (XVI) | 42627 | (2S,4S,5R,6S)-7-[[tert-butyl(dimethyl)silyl]oxy]-5-[(4-methoxybenzyl)oxy]-4,6-dimethyl-2,3-heptanediol | C23H42O5Si | 详情 | 详情 | |
| (XVII) | 42628 | (2R,3R,4S)-5-[[tert-butyl(dimethyl)silyl]oxy]-3-[(4-methoxybenzyl)oxy]-2,4-dimethylpentanal | C21H36O4Si | 详情 | 详情 | |
| (XVIII) | 42629 | (1-bromo-2-propenyl)(trimethyl)silane | 94397-40-7 | C6H13BrSi | 详情 | 详情 |
| (XIX) | 42630 | tert-butyl([(2S,3S,4S,5Z)-3-[(4-methoxybenzyl)oxy]-2,4-dimethyl-5,7-octadienyl]oxy)dimethylsilane; tert-butyl(dimethyl)silyl (2S,3S,4S,5Z)-3-[(4-methoxybenzyl)oxy]-2,4-dimethyl-5,7-octadienyl ether | C24H40O3Si | 详情 | 详情 | |
| (XX) | 42631 | (2S,3S,4S,5Z)-3-[(4-methoxybenzyl)oxy]-2,4-dimethyl-5,7-octadien-1-ol | C18H26O3 | 详情 | 详情 | |
| (XXI) | 42632 | (2R,3S,4S,5Z)-3-[(4-methoxybenzyl)oxy]-2,4-dimethyl-5,7-octadienal | C18H24O3 | 详情 | 详情 |
合成路线2
该中间体在本合成路线中的序号：(XIV)Chiral pentanoic aldehyde intermediate (XIX): The reaction of the chiral benzoate ester (XII) with (c-Hex)2B-Cl and Me2EtN in ethyl ether gives the boron enolate (XIII), which is condensed with the propionaldehyde (XIV) to yield the benzoate ester (XV). The protection of the OH group of (XV) by means of p-methoxybenzyl trichloroacetimidate and Tf-OH affords the corresponding p-methoxybenzyl ether (XVI). The reduction of the ketonic group of (XVI) by means of LiAlH4 in THF or NaBH4 in methanol provides the alcohol (XVII), which is debenzoylated with K2CO3 in methanol to furnish the diol (XVIII). Finally the vicinal diol (XVIII) is oxidized with NaIO4 in aqueous methanol to obtain the target, chiral pentanoic aldehyde intermediate (XIX).
| 【1】 Paterson, I.; Florence, G.J.; Gerlach, K.; Scott, J.P.; Sereinig, N.; A practical synthesis of (+)-discodermolide and analogues: Fragment union by complex aldol reactions. J Am Chem Soc 2001, 123, 39, 9535. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (XII) | 42623 | (1S)-1-methyl-2-oxobutyl benzoate | C12H14O3 | 详情 | 详情 | |
| (XIII) | 62838 | (1S,2E)-2-{[cyclohexyl(methyl)boryl]oxy}-1-methyl-2-butenyl benzoate | C19H27BO3 | 详情 | 详情 | |
| (XIV) | 42624 | (2S)-3-[[tert-butyl(dimethyl)silyl]oxy]-2-methylpropanal | C10H22O2Si | 详情 | 详情 | |
| (XV) | 42625 | (1S,3R,4R,5S)-6-[[tert-butyl(dimethyl)silyl]oxy]-4-hydroxy-1,3,5-trimethyl-2-oxohexyl benzoate | C22H36O5Si | 详情 | 详情 | |
| (XVI) | 42626 | (1S,3R,4R,5S)-6-[[tert-butyl(dimethyl)silyl]oxy]-4-[(4-methoxybenzyl)oxy]-1,3,5-trimethyl-2-oxohexyl benzoate | C30H44O6Si | 详情 | 详情 | |
| (XVII) | 62839 | (1S,3S,4R,5S)-6-{[tert-butyl(dimethyl)silyl]oxy}-2-hydroxy-4-[(4-methoxybenzyl)oxy]-1,3,5-trimethylhexyl benzoate | C30H46O6Si | 详情 | 详情 | |
| (XVIII) | 42627 | (2S,4S,5R,6S)-7-[[tert-butyl(dimethyl)silyl]oxy]-5-[(4-methoxybenzyl)oxy]-4,6-dimethyl-2,3-heptanediol | C23H42O5Si | 详情 | 详情 | |
| (XIX) | 42628 | (2R,3R,4S)-5-[[tert-butyl(dimethyl)silyl]oxy]-3-[(4-methoxybenzyl)oxy]-2,4-dimethylpentanal | C21H36O4Si | 详情 | 详情 |
合成路线3
该中间体在本合成路线中的序号：(II)Protection of (S)-3-hydroxy-2-methylpropionic acid methyl ester (I) as the corresponding silyl ether, followed by reduction with DIBAL provides the aldehyde (II). Diastereoselective aldol condensation of (II) with the chiral N-propionyl oxazolidinone (III) in the presence of dibutylboron triflate leads to adduct (IV), which is then reduced with LiBH4 to give the diol (V). The diol (V) is protected as the cyclic ketal (VII) by treatment with anisaldehyde dimethylacetal (VI) in the presence of pyridinium p-toluenesulfonate (PPTS). Desilylation of (VII) using tetrabutylammonium fluoride yields the alcohol (VIII). Subsequent iodination of (VIII) with I2/PPh3, followed by displacement of alkyl iodide (IX) with PPh3 in refluxing benzene, furnishes the phosphonium salt (X).
| 【1】 Choy, N.; Shin, Y.; Nguyen, P.Q.; Curran, D.P.; Balachandran, R.; Madiraju, C.; Day, B.W.; Simplified discodermolide analogues: Synthesis and biological evaluation of 4-epi-7-dehydroxy-14,16-didemethyl-(+)-discodermolides as microtubule-stabilizing agents. J Med Chem 2003, 46, 14, 2846. |
| 中间体序号 | 中间体编号 | 品名 | CAS号 | 分子式 | 供应商 | 用于合成 |
|---|---|---|---|---|---|---|
| (I) | 17128 | Methyl (2S)-3-hydroxy-2-methylpropanoate | 72657-23-9 | C5H10O3 | 详情 | 详情 |
| (II) | 42624 | (2S)-3-[[tert-butyl(dimethyl)silyl]oxy]-2-methylpropanal | C10H22O2Si | 详情 | 详情 | |
| (III) | 25713 | (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one | C13H15NO3 | 详情 | 详情 | |
| (IV) | 64732 | 3-(5-{[(1,1-dimethylethyl)(dimethyl)silyl]oxy}-3-hydroxy-2,4-dimethylpentanoyl)-4-(phenylmethyl)-1,3-oxazolidin-2-one | C23H37NO5Si | 详情 | 详情 | |
| (V) | 64733 | 5-{[(1,1-dimethylethyl)(dimethyl)silyl]oxy}-2,4-dimethyl-1,3-pentanediol | C13H30O3Si | 详情 | 详情 | |
| (VI) | 26485 | 1-(dimethoxymethyl)-4-methoxybenzene | 2186-92-7 | C10H14O3 | 详情 | 详情 |
| (VII) | 64734 | (1,1-dimethylethyl)(dimethyl)[(2-{5-methyl-2-[4-(methyloxy)phenyl]-1,3-dioxan-4-yl}propyl)oxy]silane; (1,1-dimethylethyl)(dimethyl)silyl 2-{5-methyl-2-[4-(methyloxy)phenyl]-1,3-dioxan-4-yl}propyl ether | C21H36O4Si | 详情 | 详情 | |
| (VIII) | 64735 | 2-{5-methyl-2-[4-(methyloxy)phenyl]-1,3-dioxan-4-yl}-1-propanol | C15H22O4 | 详情 | 详情 | |
| (IX) | 64736 | 4-(2-iodo-1-methylethyl)-5-methyl-2-[4-(methyloxy)phenyl]-1,3-dioxane; 4-[4-(2-iodo-1-methylethyl)-5-methyl-1,3-dioxan-2-yl]phenyl methyl ether | C15H21IO3 | 详情 | 详情 | |
| (X) | 64737 | (2-{5-methyl-2-[4-(methyloxy)phenyl]-1,3-dioxan-4-yl}propyl)(triphenyl)phosphonium iodide | C33H36IO3P | 详情 | 详情 |