Patent ID: 8592587

Claim:
A method to synthesize a compound of following formula (I)): in which: R1 and R2 are each independently a tert-butyloxycarbonyl (boc) group; R3 is a hydrogen atom, a C 1 to C 6 alkyl group, a C 1 to C 6 arylalkyl group, a C 2 to C 6 alkenyl group or an alkoxycarbonylalkyl group; Y is a —C(HR4)- group in which R4 is the hydrogen atom, a C 1 to C 6 alkyl group, an aryl group, a C 1 to C 6 arylalkyl group or a C 2 to C 6 alkenyl group; or an ortho-phenylene group, wherein it comprises: a step (a 1 ) consisting of causing to react with a base chosen from the group consisting of potassium tert-butylate, sodium hydride, lithium diisopropylamine, lithium hexamethyldisilazane, potassium hexamethyldisilazane and dimethylaminopyridine, the compound of following formula (II): in which R1, R2, R3 and Y are as previously defined, or a step (a 2 ) consisting of causing to react with a base chosen from the group consisting of potassium tert-butylate, sodium hydride, lithium diisopropylamine, lithium hexamethyldisilazane, potassium hexamethyldisilazane and dimethylaminopyridine, the compound of following formula (III): in the presence of a compound R3-X in which R1 and R2 are as defined previously, R3 is such as defined previously with the exclusion of hydrogen, and X is a halogen, or: if Y is a —C(HR4)- group, a step (a 3 ) consisting of causing the compound of following formula (IV) to react with a base chosen from the group consisting of potassium tert-butylate, sodium hydride, lithium diisopropylamine, lithium hexamethyldisilazane, potassium hexamethyldisilazane and dimethylaminopyridine: in the presence of a compound of formula R4-X in which R1, R2, R3 are as previously defined, R4 is as previously defined with the exclusion of hydrogen, and X is a halogen, or: if Y is a —C(HR4)- group, a step (a 4 ) consisting of causing to react with a base chosen from the group consisting of potassium tert-butylate, sodium hydride, lithium diisopropylamine, lithium hexamethyldisilazane, potassium hexamethyldisilazane and dimethylaminopyridine, the compound of following formula (V): in the presence of a compound of formula R4-X, in which R1 and R2 are as previously defined, R3 is identical to R4 and is as defined previously with the exclusion of hydrogen, and X is a halogen.