| abstract |
A process for manufacturing a compound of formula I: ** Formula ** or salts thereof, said process comprising: (1) demetrizing a compound of formula II with R 1 OH in the presence of a chiral reagent, to give a compound of formula III: ** Formula ** in which R 1 is selected from the group consisting of alkyl, alkenyl, aryl, aralkyl, alkylaryl, cycloalkyl, cycloalkylalkyl, cycloalkenyl and cycloalkenyl alkyl; (2) aminating the compound of formula III, to give a compound of formula IV. ** Formula ** (3) reduce the amide and ester functionalities of the compound of formula IV, obtaining a compound of formula V. ** Formula ** or salts thereof; (4) protect the amino group of the compound of formula V, to give a compound of formula VI: ** Formula ** in which P represents a protective group; (5) oxidize the compound of formula VI, to give a compound of formula VII: ** Formula ** (6) add R 2 OH to the compound of formula VII, to give a compound of formula VIII: ** Formula ** in R 2 represents H, alkyl, aryl, aralkyl, cycloalkyl or cycloalkylalkyl; (7) cyanide the compound of formula VIII, to give a compound of formula IX: ** Formula ** (8) hydrolyze the compound of formula IX with MOR 3 or R 3 OH in a compound of formula X: ** Formula * * in which M is selected from the group consisting of Li, Na and K, and R 3 is selected from the group consisting of alkyl, aryl, aralkyl and cycloalkyl; and (9) deprotecting the compound of formula X, to give the compound of formula I: or, optionally, isolating it as salts thereof. |