HCID 13205461, compound → 2H-Pyran-4-carboxylic acid, tetrahydro-, methyl ester

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Reaction Steps

The patent examples demonstrate that when operating in the gas phase in the presence of fluidized Al2O3 catalysts at a temperature of from 240° to 270° C. yields of tetrahydropyrancarboxylate of only 36 to 42% are achieved (based on 3-(2'-hydroethyl)-dihydro-2(3H)furanone used)(Examples 1 and 2). The by-products formed under these conditions comprise from 18 to 20 % of 3-(2'-methoxyethyl)-dihydro-2(3H)furanone and from 16 to 27% of 3-vinyldihydro-2(3H)furanone. Example 1b demonstrates that the by-product 3-(2'-methoxyethyl)-dihydro-2(3H)furanone can be reacted with methanol to form methyl tetrahydropyran-4-carboxylate to give a yield of 26%. On the other hand, the reaction of the by-product 3-vinyldihydro-2(3H)furanone with methanol as described in Example 1c provides a yield of only 10%.

Provenance & Evidence