Water → HCID 18370001, compound

HRID 1699973Notes

Reaction equation

HRID 1699973 reaction equation
[H-].[K+].[CH3:3][C:4]1([CH3:22])[O:8][CH:7]2[CH2:9][C:10]([CH3:21])([CH3:20])[C:11]([CH2:15][Si](C)(C)C)(O)[C:12]([CH3:13])=[C:6]2[O:5]1.O>O1CCCC1>[CH3:3][C:4]1([CH3:22])[O:8][CH:7]2[CH2:9][C:10]([CH3:21])([CH3:20])[C:11](=[CH2:15])[C:12]([CH3:13])=[C:6]2[O:5]1

Participants

5

Reactant 3

HCID 962WaterHCID 82127Potassium hydrideHCID 18370005HCID 18370005, compound2×

Product 1

HCID 18370001HCID 18370001, compoundYield 171.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

23 ml of a 20% suspension of potassium hydride in oil (containing about 3.7 g/92 mmol KH) were pipetted into a 500 ml round flask provided with a magnetic stirrer and dropping funnel having a fitted argon bubble counter and washed three times with 10 ml of hexane each time. Then, 120 ml of tetrahydrofuran were added thereto and a solution of 25.0 g (83 mmol) of 2,2,4,6,6-pentamethyl-5,6,7,7a-tetrahydro-5-trimethylsilylmethyl-1,3-benzodioxol-5-ol in 220 ml of tetrahydrofuran was added dropwise thereto at room temperature and the mixture was stirred at room temperature for 30 minutes (GC control: educt no longer present). Then, the mixture was cooled to 0° C. and 50 ml of water were slowly added dropwise. An analogous working up to that in (i) gave 29.7 g of crude 2,2,4,6,6-pentamethyl-5,6,7,7a-tetrahydro-5-methylidene-1,3-benzodioxol as a yellowish oil. A distillation on a very short Vigreux column gave at a boiling temperature of 50° C./0.02 mbar (2 Pa) 15.6 g (90% yield) of pure product as a colorless oil. 1H-NMR (CDCl3, 250 MHz): inter alia 1.12 and 1.23 (2s, in each case 3H, C(6)-(CH3)2), 1.50 and 1.53 (2s, in each case 3H, C(2)(CH3)2), 1.73 (s, 3H, C(4)-CH3), 4.55 (m, 1H, CH—O—), 4.79 (d, J=6 Hz, ═CH2); IR (film): 1693, 1112 cm−1; mass spectrum: 208 (M+, 40), 107(100);

Workup

  1. customwere pipetted into a 500 ml round flask
  2. customprovided with a magnetic stirrer
  3. custombubble counter
  4. washwashed three times with 10 ml of hexane each time
  5. additionThen, 120 ml of tetrahydrofuran were added
  6. temperatureThen, the mixture was cooled to 0° C.

Sources & evidence

ORD record
ord-faad43596a894610858c820f400689f7
Source dataset
uspto-grants-2002_02
Patent number
US06348606B2

Reaction notes

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