Patent ID: 8779170

Claim:
A process for preparing a compound of the following formula: wherein R 1 represents a cation, H, or C 1-12 alkyl, R 2 and R 3 each represent H or a hydroxy protective group, R 4 represents H or C 1-3 alkyl, and R 5 represents H or C 1-6 alkyl, comprising the steps of: (1) performing a cycloaddition reaction on the compound of the following formula: wherein in R 2a and R 6 independently represent hydroxy protecting groups, with a compound of the following formula: wherein R 7 represents C 1-6 alkoxy or C 1-12 alkyl-COOR 9 , where R 9 represents C 1-3 alkyl and R 8 represents halide or H to form a compound of the following formula: wherein R 2a , R 6 , R 7 , and R 8 are each defined above; (2) aromatizing the cyclodiene of formula (IV) to form the aromatic product of the following formula: (3) Reducing the ester of the compound of formula (V) to a benzyl alcohol and oxidation of benzyl alcohol to an aldehyde followed by addition of a carbon to said aldehyde to form an alkyne resulting in a compound of the following formula: (4) coupling the terminal alkyne with N 2 CH 2 CO 2 R 1a , wherein R 1a represents a C 1-12 alkyl followed by hydrogenation of the alkyne to its corresponding alkane to form a compound of the following formula: (5) selectively deprotecting the primary hydroxyl protective group, followed by oxidation of the primary hydroxyl group to the corresponding aldehyde, followed by coupling with a side-chain of the formula: wherein R 4 and R 5 are each defined above to form a compound of the following formula: (6) reduction of the ketone, deprotection of any remaining hydroxy protective group and optionally converting the R 1a into a cation or H to form a compound of the following formula: