Method of synthesis

Abstract

Described is a method of synthesizing 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0] octan-3-one by reacting 3-(5-ethoxyhept-1-yl) cyclopentene with dichloroketene. The resulting reaction products are reacted with acetic acid and zinc to produce 4-(5-ethoxy-hept-1-yl)bicyclo[3.2.0]heptan-6-one and 4-(5-ethoxyhept-1-yl)bicyclo[3.2.0]heptan-7-one, which are reacted with trimethylsulfonium iodide to produce 2-(5-ethoxyhept-1-yl)spiro[bicyclo[3.2.0]heptane-6,2′-oxirane] and 4-(5-ethoxyhept-1-yl)spiro-[bicyclo[3.2.0]heptane-6,2′-oxirane]. Lithium iodide is reacted with 2-(5-ethoxyhept-1-yl)spiro[bicyclo[3.2.0]heptane-6,2′-oxirane] and 4-(5-ethoxyhept-1-yl)spiro-[bicyclo-[3.2.0]heptane-6,2′-oxirane] to produce 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0]octan-3-one. A method of synthesizing 6-(5-methoxyhept-1-yl)bicyclo[3.3.0]octan-3-one is also described.

What is claimed is: 
     
         1 . A method of synthesizing a compound, the method comprising:
 reacting 3-(5-ethoxyhept-1-yl) cyclopentene with dichloroketene to form a first mixture comprising 7,7-dichloro-4-(5-ethoxyhept-1-yl)bicyclo[3.2.0]heptan-6-one and 6,6-dichloro-4-(5-eth-oxyhept-1-yl)bicyclo[3.2.0]heptan-7-one;   reacting the first mixture with acetic acid and zinc to form a second mixture comprising 4-(5-ethoxyhept-1-yl)bicyclo[3.2.0]heptan-6-one and 4-(5-ethoxyhept-1-yl) bicyclo[3.2.0]heptan-7-one;   reacting the second mixture with trimethylsulfonium iodide to form a third mixture comprising 2-(5-ethoxyhept-1-yl)spiro[bicyclo[3.2.0]heptane-6,2′-oxirane] and 4-(5-ethoxyhept-1-yl)-spiro-[bicyclo-[3.2.0]heptane-6,2!-oxirane]; and   reacting the third mixture with lithium iodide to form 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0]octan-3-one.   
     
     
         2 . The method according to  claim 1 , wherein reacting 3-(5-ethoxyhept-1-yl) cyclopentene with dichloroketene to form a first mixture comprises reacting the 3-(5-ethoxyhept-1-yl) cyclopentene with trichloroacetyl chloride and zinc. 
     
     
         3 . The method according to  claim 2 , wherein reacting the 3-(5-ethoxyhept-1-yl) cyclopentene with trichloroacetyl chloride and zinc to form a first mixture comprises dissolving 3-(5-ethoxyhept-1-yl) cyclopentene in an organic solvent, dissolving zinc powder in the organic solvent, and adding a solution of trichloroacetyl chloride to the organic solvent. 
     
     
         4 . The method according to  claim 2 , wherein reacting the 3-(5-ethoxyhept-1-yl) cyclopentene with trichloroacetyl chloride and zinc to form a first mixture comprises reacting reagents consisting of 3-(5-ethoxyhept-1-yl) cyclopentene, trichloroacetyl chloride, and zinc. 
     
     
         5 . The method according to  claim 1 , wherein reacting 3-(5-ethoxyhept-1-yl) cyclopentene with dichloroketene to form a first mixture comprising 7,7-dichloro-4-(5-ethoxyhept-1-yl)bicyclo[3.2.0]heptan-6-one and 6,6-dichloro-4-(5-ethoxyhept-1-yl)bicyclo[3.2.0]heptan-7-one comprises filtering and concentrating the first mixture comprising 7,7-dichloro-4-(5-ethoxyhept-1-yl) bicyclo[3.2.0]heptan-6-one and 6,6-dichloro-4-(5-ethoxyhept-1-yl)bicyclo[3.2.0]heptan-7-one. 
     
     
         6 . The method according to  claim 1 , wherein reacting the first mixture with acetic acid and zinc to form a second mixture comprises reacting the first mixture with acetic acid and zinc without distilling the first mixture. 
     
     
         7 . The method according to  claim 1 , wherein reacting the second mixture with trimethylsulfonium iodide to form a third mixture comprises adding trimethylsulfonium iodide, sodium hydride, and dimethylsulfoxide to the second mixture. 
     
     
         8 . The method according to  claim 1 , wherein reacting the third mixture with lithium iodide to form 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0]octan-3-one comprises dissolving the 2-(5-ethoxyhept-1-yl)spiro[bicyclo[3.2.0]heptane-6,2′-oxirane] and 4-(5-ethoxyhept-1-yl)spiro[bicyclo[3.2.0]heptane-6,2′-oxirane] in tetrahydrofuran and adding a solution of lithium iodide in tetrahydrofuran. 
     
     
         9 . The method according to  claim 1 , wherein reacting the third mixture with lithium iodide to form 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0]octan-3-one comprises filtering and concentrating the 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0]octan-3-one. 
     
     
         10 . The method according to  claim 1 , further comprising purifying the 6-(5-ethoxyhept-1-yl)bicyclo[3.3.0]octan-3-one.