反応 #2507839

反応方程式

chloroenal

NaOH

Phosphorus oxychloride

chloroenal

sodium hydrogen carbonate

1-(3-propoxy-5,6,7,8-tetrahydro-5,5,8,8,-tetramethylnaphthalen-2-yl)ethanone

→

6-ethynyl-1,1,4,4,-tetramethyl-7-propoxy-1,2,3,4-tetrahydronaphthalene

収率 39.0%

溶媒

dioxane water

dioxane H2O

dimethyl formamide

brine

反応条件

後処理

1. 1
   workup.STIRRINGwas stirred for 12 hours
2. 2
   抽出Ethyl acetate extraction
3. 3
   その他afforded the crude product
4. 4
   workup.STIRRINGthe reaction mixture was stirred for 2 hours
5. 5
   その他to yield an orange reaction solution
6. 6
   温度The reaction solution was cooled to room temperature
7. 7
   抽出extracted with EtOAc
8. 8
   乾燥The organic phase was dried (MgSO4)
9. 9
   ろ過filtered
10. 10
    濃縮concentrated
11. 11
    その他to afford an orange oil which
12. 12
    その他was purified by radial chromatography (10:1 hexane:ethyl acetate)

実験手順

Phosphorus oxychloride (0.234 grams, 0.142 ml, 1.52 mmol) was added dropwise to dimethyl formamide (DMF) (4 ml) at room temperature under a nitrogen atmosphere. The solution was stirred for 30 minutes. The 1-(3-propoxy-5,6,7,8-tetrahydro-5,5,8,8,-tetramethylnaphthalen-2-yl)ethanone was added quickly (in one portion) to the orange solution, the reaction solution was heated to 60° C. and was stirred for 12 hours. The obtained dark brown solution was poured into ice water and the aqueous layer was adjusted to pH 7 with solid sodium hydrogen carbonate. Ethyl acetate extraction afforded the crude product, the chloroenal (6-[1-hydroxy,2-chloro-ethenyl]-1,1,4,4-tetramethyl-7-propoxy-1,2,3,4-tetrahydronaphthalene), 0.128 grams, as an orange/brown oil. A solution of the crude chloroenal in dioxane:water (3:2; 5 ml) was added to a solution of NaOH (0.061 grams, 1.52 mmol) in dioxane: H2O (3:2; 20 ml), at 80° C., and the reaction mixture was stirred for 2 hours, to yield an orange reaction solution. The reaction solution was cooled to room temperature, poured into brine and extracted with EtOAc. The organic phase was dried (MgSO4), filtered, and concentrated to afford an orange oil which was purified by radial chromatography (10:1 hexane:ethyl acetate) to give the product 6-ethynyl-1,1,4,4,-tetramethyl-7-propoxy-1,2,3,4-tetrahydronaphthalene (39%) as a yellow oil [1H-NMR (400 MHz, CDCl3): d 7.38(s, 1H, Ar—H), 6.76(s,1H, Ar—H), 3.98 (t, J=6.6 Hz, 2H, OCH3), 3.19 (s, 1H, CH),1.83 (m, 2H, CH2),1.66 (m, 2H, 2CH2),1.26 (s, 6H, 2CH3),1.23 (s, 6H, 2CH3), 0.93 (t, J=7.4 Hz, 3H, CH3)].

出典