反応 #607397

反応方程式

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

溶媒

tetrahydrofuran

THF

反応条件

後処理

1. 1
   その他the ice bath was removed
2. 2
   workup.STIRRINGThe resulting solution was stirred at ambient temperature overnight
3. 3
   その他The reaction was quenched with saturated aqueous ammonium chloride solution (200 ml) and water (200 ml)
4. 4
   抽出extracted with ethyl acetate (3×150 ml)
5. 5
   乾燥The combined organic solution was dried (MgSO4)
6. 6
   ろ過filtered
7. 7
   濃縮concentrated
8. 8
   その他The residue was purified on a silica gel column
9. 9
   洗浄eluted with ethyl acetate and hexane

実験手順

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.

出典