Patent ID: 7314942

Claim:
A process for preparing α-methylenelactones of Formula II comprising forming a reaction mixture comprising lactones of Formula I, a formaldehyde, and carbon dioxide solvent, wherein, n=1-11; R 1 , R 2 , R 3 and R 4 taken independently are selected from the group consisting of hydrogen, hydrocarbyl or substituted hydrocarbyl, C 1 -C 18 unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted cycloalkyl containing at least one heteroatom unsubstituted or substituted aromatic ring, and unsubstituted or substituted aromatic ring containing at least one heteroatom; and any two of R 1 , R 2 , R 3 and R 4 together can optionally form a ring, and subjecting the reaction mixture to a temperature from about 70° to about 400° C. and pressure sufficient to cause the reaction mixture to exist as a supercritical fluid phase in contact with a catalyst capable of converting the lactones of Formula I to the α-methylenelactones of Formula II.