Process for producing 1,2-cis-2 fluorocyclopropane- 1carboxylic ester compound

A process for producing a compound represented by formula (3):

• [wherein R1 represents a C1-C8 alkyl group, a C6-C12 aryl group, a C2-C8 alkenyl group, or a C7-C26 aralkyl group], which process is characterized by comprising reacting a compound represented by formula (1):
• [wherein X1 represents a hydrogen atom, a chlorine atom, a bromine atom, or an iodine atom;
• X2 represents a hydrogen atom, a chlorine atom, a bromine atom, or an iodine atom;
• when one of X1 and X2 is a chlorine atom, a bromine atom, or an iodine atom, the other is a hydrogen atom;
• i.e., X1 and X2 are not simultaneously hydrogen atoms;
• and R1 has the same meaning as defined in formula (3)] with a reducing agent represented by formula (2):
• M1BHmR2n (2-1)
• or
• M2(BHmR2n)2 (2-2)
• [wherein M1 represents an alkali metal atom;
• M2 represents an alkaline earth metal atom or a zinc atom;
• R2 represents a hydrogen atom, a cyano group, a C1-C8 acyloxy group, or a C1-C6 alkoxy group;
• m represents an integer from 1 to 4;
• n represents an integer from 0 to 3;
• and the sum of m and n is 4] in the presence of an aprotic polar solvent, and one or more Lewis acids selected from among halides and trifluoromethanesulfonic acid salts (triflates) of an atom selected from among boron, magnesium, aluminum, silicon, scandium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, yttrium, zirconium, silver, cadmium, indium, tin, antimony, hafnium, lead, bismuth, lanthanum, cerium, and ytterbium.