Patent ID: 6797832
Filing Date: 2004-09-28
Classification: C07C,C07D,Y02P

Abstract:
A production method of a 5-oxy-7-oxabicyclo[4.1.0]hept-3-ene-3-carboxylic acid ester of the formula (X) wherein R1 and R3 are independently an alkyl group optionally having substituents, a cycloalkyl group optionally having substituents, an alkenyl group optionally having substituents, an aryl group optionally having substituents or an aralkyl group optionally having substituents, which comprises: reacting a 2-halogeno-7-oxabicyclo[2.2.1]heptane-5,3-carbolactone of the formula (I) â€ƒwherein X is a halogen atom, with a base, reacting the resulting compound with alkyl halide optionally having substituents, cycloalkyl halide optionally having substituents, alkenyl halide optionally having substituents, aryl halide optionally having substituents or aralkyl halide optionally having substituents, to give a 2,3-epoxy-7-oxabicyclo[2.2.1]heptane-5-carboxylic acid ester of the formula (III) â€ƒwherein R1 is as defined above, reacting the obtained 2,3-epoxy-7-oxabicyclo[2.2.1]heptane-5-carboxylic acid ester with a base to give a 5-hydroxy-7-oxabicyclo[4.1.0]hept-2-ene-3-carboxylic acid ester of the formula (IV) â€ƒwherein R1 is as defined above, protecting a hydroxyl group of the obtained 5-hydroxy-7-oxabicyclo[4.1.0]hept-2-ene-3-carboxylic acid ester to give a 5-oxy-7-oxabicyclo[4.1.0]hept-2-ene-3-carboxylic acid ester of the formula (V) â€ƒwherein R1 is as defined above and R2 is a hydroxyl-protecting group, reacting the obtained 5-oxy-7-oxabicyclo[4.1.0]hept-2-ene-3-carboxylic acid ester with an alcohol of the formula (VI) R3OHâ€ƒâ€ƒ(VI) â€ƒwherein R3 is as defined above, in the presence of a Lewis acid to give a 4-hydroxy-3,5-dioxy-1-cyclohexene-1-carboxylic acid ester of the formula (VII) â€ƒwherein R1, R2 and R3 are as defined above, reacting the obtained 4-hydroxy-3,5-dioxy-1-cyclohexene-1-carboxylic acid ester with a sulfonylating agent in the presence of a base to give a 3,5-dioxy-4-sulfonyloxy-1-cyclohexene-1-carboxylic acid ester of the formula (VIII) â€ƒwherein R1, R2 and R3 are as defined above and A is an organic sulfonyl group, removing the R2 from the obtained 3,5-dioxy-4-sulfonyloxy-1-cyclohexene-1-carboxylic acid ester to give a 5-hydroxy-3-oxy-4-sulfonyloxy-1-cyclohexene-1-carboxylic acid ester of the formula (IX) â€ƒwherein A, R1 and R3 are as defined above, and reacting the obtained 5-hydroxy-3-oxy-4-sulfonyloxy-1-cyclohexene-1-carboxylic acid ester with a base.