The Vespiary

The Hive => Chemistry Discourse => Topic started by: wolff_kishner on July 10, 2004, 12:38:00 AM

Title: Acetals as grignard solvents?
Post by: wolff_kishner on July 10, 2004, 12:38:00 AM
Would acetals be acceptable solvents for grignard reactions? In basic conditions, acetals are stable ethers. Since Grignard reactions take place in a basic environment, wouldn't the acetal be indistinguishable from an ether?

I have used the search engine and found nothing either supporting or opposing the use of acetals.
Title: Dialkoxymethanes/formaldehyde acetals
Post by: Rhodium on July 10, 2004, 12:50:00 AM
Dimethoxymethane and diethoxymethane are both very good solvents for Grignard reactions:

http://www.arkat-usa.org/ark/journal/2002/Spinelli/MS-568H/568H.pdf (http://www.arkat-usa.org/ark/journal/2002/Spinelli/MS-568H/568H.pdf)



Title: Why aren't they widely used then?
Post by: wolff_kishner on July 10, 2004, 03:35:00 AM
Thanks, Rhodium. However, if formaldehyde acetals are good grignard solvents, why aren't they popular? Diethoxymethane would be easy to make and less volatile and dangerous than ethyl ether.
Title: price
Post by: Rhodium on July 10, 2004, 05:24:00 AM
They are more expensive than ether, and in case an acidic workup is made, formaldehyde may contaminate or react with the product.