Cyclopentadiene → HCID 86590327, compound

HRID 735279Notes

Reaction equation

HRID 735279 reaction equation
[CH3:1][CH:2]([CH3:9])[CH:3]=[CH:4][C:5](=[O:8])[CH2:6][CH3:7].[CH:10]1[CH2:14][CH:13]=[CH:12][CH:11]=1.Cl(O)(=O)(=O)=O.C([C@@H]1N[C@H](C2OC(C)=CC=2)N(C)C1=O)C1C=CC=CC=1>O>[CH:2]([C@H:3]1[C@@H:12]2[CH2:13][C@H:14]([CH:10]=[CH:11]2)[C@H:4]1[C:5](=[O:8])[CH2:6][CH3:7])([CH3:9])[CH3:1]

Participants

6

Reactant 4

HCID 7612Cyclopentadiene2×HCID 24247Perchloric AcidHCID 11303220(2S,5S)-(-)-5-Benzyl-3-methyl-2-(5-methyl-2-furyl)-4-imidazolidinoneHCID 54090841HCID 54090841, compound

Product 1

HCID 86590327HCID 86590327, compoundYield 78%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

Prepared according to general procedure A from 6-methylhept-4-en-3-one (89 μL, 0.60 mmol), cyclopentadiene (99 μL, 1.2 mmol), 70% aqueous perchloric acid (10.3 μL, 0.12 mmol) and (2S, 5S)-5-benzyl-3-methyl-2-(5-methyl-furan-2-yl)-imidazolidin-4-one (32 mg, 0.12 mmol) in water (120 μL) for 2.5 days at 0° C. Then, an additional 1.2 mmol of cyclopentadiene was added and the mixture was allowed to stir for an additional 3.5 days at 0° C. Purification by silica gel chromatography (18:1 pentane:ether) provided the title compound as a colorless oil in 78% yield (90 mg, 0.47 mmol); 6:1 endo:exo, endo 90% ee. For the purpose of characterization, the more quickly eluting exo diastereomer was removed by silica gel chromatography as above. IR (film) 3057, 2961, 2869, 1709, 1460, 1367, 1334, 1136, 1028, 904.2, 716.6 cm−1; 1H NMR (300 MHz, CDCl3) δ 6.26 (dd, J=5.7, 3.3 Hz, 1H, CH═CH), 5.79 (dd, J=5.7, 2.7 Hz, 1H, CH═CH), 3.14 (m, 1H, CHCH═CH), 2.77 (m, 1H, CHCH═CH), 2.63 (dd, J=3.6, 3.6 Hz, 1H, CHCO), 2.49 (m, 2H, CH2CO), 1.40 (m, 3H, CH(CH3)2 and CHCH2CH), 1.05 (d, J=7.5 Hz, 3H, one of CH(CH3)2), 0.99 (dd, J=4.8, 4.8 Hz, 3H, CH2CH3), 0.84 (d, J=7.5 Hz, 3H, one of CH(CH3)2), 13C NMR (75 MHz, CDCl3) δ 211.6, 139.6, 131.9, 57.8, 49.1, 47.4, 47.2, 45.5, 35.2, 33.1, 22.7, 22.2, 8.5; HRMS (CI) exact mass calc'd for (C13H20O) requires m/z 192.1514, found m/z 192.1513. [α]D=+20.1 (c=1.0, CHCl3). Product ratios were determined by GLC analysis (162° C., 23 psi); (1R, 2R, 3S, 4R) endo isomer tr=4.4 min, and (1S, 2S, 3R, 4S) endo isomer tr=4.2 min, exo isomers tr=3.9, 4.1 min.

Workup

  1. customPrepared
  2. customPurification by silica gel chromatography (18:1 pentane:ether)

Sources & evidence

ORD record
ord-229be1b2b04548f7aa3aa0b9673fdfca
Source dataset
uspto-grants-2009_09
Patent number
US07592463B2

Reaction notes

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