Dimethyl 3-cyclopentene-1,1-dicarboxylate → [1-(Hydroxymethyl)cyclopent-3-en-1-yl]methanol

온도

0 °C

The desired diol was prepared via LAH reduction of the corresponding diester 2. To a flame dried round-bottomed flask was placed lithium aluminum hydride (LAH, Aldrich, 95%, 6.99 g, 175 mmol) and anhydrous tetrahydrofuran (THF, 235 mL). The resulting suspension was cooled to 0° C. and then a solution of the dimethyl diester 2 in 58 mL of anhydrous THF was added dropwise via an additional funnel. The resulting mixture was allowed to stir at 0° C. for 4 hours while monitored by TLC. The reaction mixture was then carefully quenched by sequential addition of 6 mL of water, 6 mL of 3 N aqueous solution of NaOH and 17.5 mL of water. The resulting mixture was allowed to slowly come to room temperature and then filtered through a bed of celite. The resultant solid cake was washed repeatedly with refluxing THF (total of 250 mL). The filtrate was dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford alight yellow oil which was dissolved in 10 mL of refluxing toluene and the water was azeotropically removed, removal of the remaining toluene gave an off-white solid, which was recrystallized from refluxing toluene. The desired diol 3 was obtained as white needles in 86.2% yield, Mp (DSC) 81.21° C.; 1H-NMR (CD13, 300 MHz) δ5.59 (s, 2H), 3.73 (s, 2H), 3.63 (s, 4H), 2.16 (s, 4H); 13C-NMR (CD13, 300 MHz) δ128.69, 69.19, 47.53, 38.61; FT-IR (CH2Cl2) (cm−1) 3323, 3055, 2918, 2846, 1619, 1442, 1419, 1357, 1266, 1114, 1093, 1025, 955, 909, 896.

1. customTo a flame dried round-bottomed flask was placed
2. customThe reaction mixture was then carefully quenched by sequential addition of 6 mL of water, 6 mL of 3 N aqueous solution of NaOH and 17.5 mL of water
3. customto slowly come to room temperature
4. filtrationfiltered through a bed of celite
5. washThe resultant solid cake was washed repeatedly with refluxing THF (total of 250 mL)
6. dry with materialThe filtrate was dried over anhydrous sodium sulfate
7. concentrationconcentrated under reduced pressure
8. customto afford alight yellow oil which
9. customthe water was azeotropically removed
10. customremoval of the remaining toluene
11. customgave an off-white solid, which
12. customwas recrystallized
13. temperaturefrom refluxing toluene

ORD 기록

ord-44888201efcc41cea745caf4d4066478

출처 데이터셋

uspto-grants-2002_10

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US06458865B2