반응 #607397

반응 방정식

solution

(2Z,4E)-methyl 5-((S)-1-hydroxy-2,6,6-trimethyl-4-oxocyclohex-2-en-1-yl)-3-methylpenta-2,4-dienoate

methyl iodide

Lithium hexamethyl disilazane

→

title compound

(2Z,4E)-methyl 5-((S)-1-hydroxy-2,3,6,6-tetramethyl-4-oxocyclohex-2-en-1-yl)-3-methylpenta-2,4-dienoate

용매

tetrahydrofuran

THF

반응 조건

후처리

1. 1
   기타the ice bath was removed
2. 2
   workup.STIRRINGThe resulting solution was stirred at ambient temperature overnight
3. 3
   기타The reaction was quenched with saturated aqueous ammonium chloride solution (200 ml) and water (200 ml)
4. 4
   추출extracted with ethyl acetate (3×150 ml)
5. 5
   건조The combined organic solution was dried (MgSO4)
6. 6
   여과filtered
7. 7
   농축concentrated
8. 8
   기타The residue was purified on a silica gel column
9. 9
   세척eluted with ethyl acetate and hexane

실험 절차

A solution of Example 1a (27.8 g, 0.1 mole) in anhydrous tetrahydrofuran (THF, 600 ml) was cooled to 0° C. with an ice bath under an atmosphere of nitrogen. Lithium hexamethyl disilazane (1.0 M solution in THF, 150 ml) was added dropwise via a syringe over about 30 minutes. The resulting solution was stirred at 0° C. for 30 minutes and the ice bath was removed. A solution of methyl iodide (8.09 ml, 18.4 g, 0.13 mole) in anhydrous THF (20 ml) was added via a syringe over 20 minutes. The resulting solution was stirred at ambient temperature overnight. The reaction was quenched with saturated aqueous ammonium chloride solution (200 ml) and water (200 ml) and extracted with ethyl acetate (3×150 ml). The combined organic solution was dried (MgSO4), filtered and concentrated. The residue was purified on a silica gel column eluted with ethyl acetate and hexane. The title compound was obtained as a white solid (17.1 g). 1HNMR (CDCl3): δ7.84 (d, 1H), 6.16 (d, 1H), 5.75 (s, 1H), 3.70 (s, 3H), 2.44 (d, 1H), 2.34 (d, 1H), 2.00 (s, 3H), 1.88 (s, 3H), 1.83 (s, 3H), 1.07 (s, 3H), 1.00 (s, 3H). MS (ESI—): m/e=291.

출처