Questions regarding new route to Phenyl acetone, from ramberg Backlund reaction.

Jack

Don't buy from me
Resident
Joined
Oct 24, 2021
Messages
53
Reaction score
18
Points
8
While reading Erowid (https://erowid.org/archive/rhodium/chemistry/phenylacetone.html) A pathway stood out which was a wittig reaction between benzaldehyde and the triphenylphosphonium salt of alpha chloro ethyl methyl ether, the product of this reaction is an enol methyl ether which can be reacted with hydrochloric acid to form the ketone. The conditions of this reaction that make it unpractical is that potassium tert butoxide, and triphenyl phosphine are exotic reagents, however it is known that alpha chloro sulfones can be reacted with a base such as alkali metal hydroxides to form an episulfone which is extruded to form an alkene (https://en.wikipedia.org/wiki/Ramberg–Bäcklund_reaction). Alpha halo ethers are easily made from symmetrical acetals in this case dimethoxyethane the acetal of acetaldehyde (http://www.orgsyn.org/demo.aspx?prep=v84p0102) and then in presence of supposedly non nucleophilic bases such as Hünig's base, could be reacted with benzyl mercaptan to form a thiol ether. It is known that thio ethers can be oxidised easily to sulfones with the use of bleach and the sulfone can then be chlorinated with some chlorinating agent (https://doi.org/10.1080/00304949609356529). However I have not been able to find a reference of a ramberg backlund reaction which produces enol ethers other than when said enol ether is cyclic (https://sci-hub.hkvisa.net/10.1002/1099-0690(200204)2002:7<1305::aid-ejoc1305>3.0.co;2-0). It is also known that if an epoxide is beside the sulfone an allylic alcohol is produced (https://sci-hub.hkvisa.net/https://doi.org/10.1016/S0040-4039(97)00507-8). If anybody could help me find information pertaining to this reaction their help would be greatly appreciated.

Images: Enol ether (E)-(2-methoxyprop-1-en-1-yl)benzene, http://linx4f75phtm63mxalb2wtspofcodku5lwofiyoupda4n4uc6cfjuzid.onion/nflvbqrt.png
alpha chloro ethyl methyl ether, http://linx4f75phtm63mxalb2wtspofcodku5lwofiyoupda4n4uc6cfjuzid.onion/dvxeeir2.png
The sulfone, http://linx4f75phtm63mxalb2wtspofcodku5lwofiyoupda4n4uc6cfjuzid.onion/y8u79ffx.png
 
Last edited:

WillD

Expert
Joined
Jul 19, 2021
Messages
774
Reaction score
1,060
Points
93
Long way and exp. Metal alkooxide not a problem in China (solutions). If u have benzaldehyde, chloroether and Me-oxide best way will be the Darzen reaction.
 
Top