• English
  • 简体中文
Login Register
Current Location: Home > Feedback Help Print

【结 构 式】

【分子编号】45752

【品名】ethyl (E)-7-bromo-5-(2-bromoethyl)-2-methyl-2-heptenoate

【CA登记号】

【 分 子 式 】C12H20Br2O2

【 分 子 量 】356.0976

【元素组成】C 40.48% H 5.66% Br 44.88% O 8.99%

与该中间体有关的原料药合成路线共 1 条

合成路线1

该中间体在本合成路线中的序号:(IX)

A stereoselective synthesis of beta-elemene has been reported: Reaction of 2-allylpropane-1,3-diol (I) with tosyl chloride and pyridine gives the ditosylate (II), which is treated with NaCN in refluxing DMF to yield the dinitrile (III). The methanolysis of (III) with TsOH and refluxing methanol affords the dicarboxylic acid (IV), which is reduced with LiAlH4 in THF providing 3-allyl-1,5-pentanediol (V). The reaction of (V) with CBr4 and PPh3 in dichloromethane gives the dibromide (VI), which is ozonolyzed with ozone and PPh3 in dichloromethane to yield the aldehyde (VII). Condensation of (VII) with the phosphorane (VIII) in dichloromethane affords the unsaturated ester (IX), which is reduced with DIBAL in toluene to afford alcohol (X). Condensation of (X) with triethyl orthopropionate (XI) in refluxing phenol/toluene gives the anti-dibromoester (XII), along with some syn-isomer that is easily separated. Cyclization of (XII) with LDA in THF yields the cyclohexanecarboxylate (XIII), which is treated with t-BuOK in THF to afford the divinylcylohexanecarboxylate (XIV). Reduction of (XV) with DIBAL in toluene provides the carbinol (XV), which is treated with CuCl, PdCl2 and O2 in DMF/water giving the acetyl derivative (XVI). Oxidation of (XVI) with PCC and AcONa in dichloromethane gives keto-aldehyde (XVII), which is finally submitted to a double Wittig methylenation with methylenetriphenylphosphorane (XVIII) in THF.

1 Lee, J.; Kim, S.; Kim, D.; Chang, J.; Stereoselective synthesis of (±)-beta-elemene by a doubly diastereodifferentiating internal alkylation: A remarkable difference in the rate of enolization between syn and anti esters. Tetrahedron 2001, 57, 7, 1247.
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) 45745 2-allyl-1,3-propanediol C6H12O2 详情 详情
(II) 45746 2-([[(4-methylphenyl)sulfonyl]oxy]methyl)-4-pentenyl 4-methylbenzenesulfonate C20H24O6S2 详情 详情
(III) 45747 3-allylpentanedinitrile C8H10N2 详情 详情
(IV) 45748 dimethyl 3-allylpentanedioate C10H16O4 详情 详情
(V) 45749 3-allyl-1,5-pentanediol C8H16O2 详情 详情
(VI) 45750 6-bromo-4-(2-bromoethyl)-1-hexene C8H14Br2 详情 详情
(VII) 45751 5-bromo-3-(2-bromoethyl)pentanal C7H12Br2O 详情 详情
(VIII) 37071 ethyl 2-(triphenylphosphoranylidene)propanoate 5717-37-3 C23H23O2P 详情 详情
(IX) 45752 ethyl (E)-7-bromo-5-(2-bromoethyl)-2-methyl-2-heptenoate C12H20Br2O2 详情 详情
(X) 45753 (E)-7-bromo-5-(2-bromoethyl)-2-methyl-2-hepten-1-ol C10H18Br2O 详情 详情
(XI) 10395 1,1,1-Triethoxypropane; 1,1-Diethoxypropyl ethyl ether; Triethyl orthopropionate 115-80-0 C9H20O3 详情 详情
(XII) 45754 ethyl (2R,3R)-3-[4-bromo-2-(2-bromoethyl)butyl]-2,4-dimethyl-4-pentenoate C15H26Br2O2 详情 详情
(XIII) 45755 ethyl (1R,2S,4R)-4-(2-bromoethyl)-2-isopropenyl-1-methylcyclohexanecarboxylate 74181-34-3 C15H25BrO2 详情 详情
(XIV) 45756 ethyl (1R,2S,4R)-2-isopropenyl-1-methyl-4-vinylcyclohexanecarboxylate C15H24O2 详情 详情
(XV) 45757 [(1R,2S,4R)-2-isopropenyl-1-methyl-4-vinylcyclohexyl]methanol C13H22O 详情 详情
(XVI) 45758 1-[(1R,3S,4R)-4-(hydroxymethyl)-3-isopropenyl-4-methylcyclohexyl]-1-ethanone C13H22O2 详情 详情
(XVII) 45759 (1R,2S,4R)-4-acetyl-2-isopropenyl-1-methylcyclohexanecarbaldehyde C13H20O2 详情 详情
(XVIII) 27301 methylene(triphenyl)phosphorane C19H17P 详情 详情
Extended Information