Hexane → (E)-1-bromo-2-(2-(2,6,6-trimethyl-1-cyclohexen-1-yl)ethenyl)-cyclohexene

HRID 1603266노트

반응식

HRID 1603266 반응식
[Cl-].[CH3:2][C:3]1[CH2:8][CH2:7][CH2:6][C:5]([CH3:10])([CH3:9])[C:4]=1[CH2:11][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C([Li])CCC.[Br:36][C:37]1[CH2:42][CH2:41][CH2:40][CH2:39][C:38]=1[CH:43]=O.CCCCCC>O1CCCC1>[Br:36][C:37]1[CH2:42][CH2:41][CH2:40][CH2:39][C:38]=1/[CH:43]=[CH:11]/[C:4]1[C:5]([CH3:9])([CH3:10])[CH2:6][CH2:7][CH2:8][C:3]=1[CH3:2]

참가 물질

6

반응물 4

HCID 8058HexaneHCID 112639462-Bromocyclohexene-1-carbaldehydeHCID 19609258((2,6,6-Trimethyl-1-cyclohexen-1-yl)methyl)triphenylphosphonium chlorideHCID 178418339Butyllithium

생성물 1

HCID 19609259(E)-1-bromo-2-(2-(2,6,6-trimethyl-1-cyclohexen-1-yl)ethenyl)-cyclohexene수율 97.7%

시약·촉매·용매 1

HCID 8028Tetrahydrofuran용매2회

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온도
-60 °C

실험 절차

A suspension of ((2,6,6-trimethyl-1-cyclohexen-1-yl)methyl)triphenylphosphonium chloride (18 g) in tetrahydrofuran (300 ml) was cooled to -60° C., treated dropwise with n-butyllithium (1.4M in hexane; 32 ml), and then stirred a further 10 minutes. To this cold solution was added the 2-bromocyclohexene-1-carboxaldehyde (8.5 g,75% pure by HNMR analysis) dissolved in tetrahydrofuran, and the mixture was allowed to warm to room temperature after which it was stirred for a further 2 hours. Hexane was then added to the reaction and the resulting mixture was washed with water, 50% aqueous methanol and dried (magnesium sulphate). Removal of the solvents yielded the crude (E)-1-bromo-2-(2-(2,6,6-trimethyl-1-cyclohexen-1-yl)ethenyl)-cyclohexene (12.5 g) as a mixture of isomers which was used, as is, in the next step. Standard transmetalation and reaction with DMF yielded a cruce aldehyde (4.5 g) which was dissolved in tetrahydrofuran (100 ml) and reacted with an excess of the phosphonate as in Example 1to give methyl (2E,4E)-3-methyl-5-(2-((E)-2(2,6,6-trimethyl-cyclohexen-1-yl)ethenyl)-1-cyclohexen-1-yl)-2,4-pentadienoate (3 g) as an oil after purification by HPLC (2.5% ether in hexane). Hydrolysis with aqueous potassium hydroxide solution gave crystalline (2E,4E)-3-Methyl-5-(2-((E)-2(2,6,6-trimethyl-cyclohexen-1-yl)ethenyl)-1-cyclohexen-1-yl)-2,4-pentadienoic acid (1.6 g from hexane-tetrahydrofuran).

후처리

  1. temperatureto warm to room temperature after which it
  2. stirringwas stirred for a further 2 hours
  3. washthe resulting mixture was washed with water, 50% aqueous methanol
  4. dry with materialdried (magnesium sulphate)
  5. customRemoval of the solvents

출처 및 근거

ORD 기록
ord-e8847c762d1e41d1818f55cc4060de33
출처 데이터셋
uspto-grants-1999_11
특허 번호
US05986131

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