A novel synthesis of allyl vinyl ethers

✍ Scribed by J.C. Gilbert; U. Weerasooriya; B. Wiechman; L. Ho

• Publisher: Elsevier Science
• Year: 1980
• Tongue: French
• Weight: 251 KB
• Volume: 21
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)71116-6

✦ Synopsis

Base-promoted reaction of dimethyt d~usomet~~zp~sp~~te (21 with aZipkatic ketones -in the presence of aZlylie alcohols affords aldehydio atlyZ vi?fyZ ethers (:I. Ally1 vinyl ethers, 4, are of interest because they undergo the Claisen rearrangement, 2 a sequence that accomplishes net a-allylation of carbonyl compounds (eq. 1). Modern methods for the preparation of aliphatic ethers have typically involved heating an excess of the car-bony1 compound, as its ketal or as a simple enol ether, with the appropriate allylic alcohol. and a catalytic amount of acid. 3a For those cases in which the alcohol is the more expendable reagent, it is used in large excess relative to the carbonyl component. 3b The ether 1 that results is normally not isolable4 but undergoes rearrangement under the reaction conditions.3c le 0 2 Rl R2 -