Formaldehyde → 2,2,3-Trimethyl-α-methylene-3-cyclopentene-1-acetaldehyde
Reaction equation
[OH-].[Na+].C=O.[CH3:5]CCCCC.[CH3:11][C:12]1[C:16]([CH3:18])([CH3:17])[CH:15]([CH2:19][CH:20]=[O:21])[CH2:14][CH:13]=1>CO.O>[CH3:18][C:16]1([CH3:17])[C:12]([CH3:11])=[CH:13][CH2:14][CH:15]1[C:19](=[CH2:5])[CH:20]=[O:21]Participants
Conditions
- Temperature
- 0 °C
Procedure
A 3 liter 3 neck round bottomed flask was charged with 50 g of sodium hydroxide (1.25 moles) in 250 g of methanol. 200 g of paraformaldehyde, 500 g of hexane and 2.5 g of BHA were added and the flask was cooled to 0° C. With fast agitation 500 g of campholenic aldehyde at a purity of 88.9% (2.92 moles) were added dropwise over 70 minutes keeping the temperature at 0°-5° C. The batch was stirred for 3 hours at 0° C. Then 50 ml of water was added and the layers are separated. The water layer was back extracted with 250 ml of hexane. The hexane extracts were combined and washed with 2×500 ml of 10% sodium hydroxide and 3×500 ml of water. The batch was dried and afforded 1163 g of crude 2-(2,2,3-trimethylcyclopent-3-en-1-yl)propenal in hexane. A second batch was prepared analogously affording 1169 g of crude product.
Workup
- customat 0°-5° C
- customthe layers are separated
- extractionThe water layer was back extracted with 250 ml of hexane
- washwashed with 2×500 ml of 10% sodium hydroxide and 3×500 ml of water
- customThe batch was dried
Sources & evidence
- ORD record
- ord-163af83573ed42358ca8bac5111319fe
- Source dataset
- uspto-grants-1996_04
- Patent number
- US05510326
Reaction notes
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