| 摘要 |
This disclosure relates to process for the preparation of a compound of formula (I) wherein R is hydrogen, a straight or branched C1-C6 alkyl-carbonyl group or a phenylcarbonyl group, or a salt thereof, comprising the following steps: a) adding to a suspension of Mg a compound of formula (II) R1(MgX)n—LiY wherein n is 1 or 2; R1 is an aromatic, aliphatic, carbocyclic or heterocyclic organic group having 1 to 24 carbon atoms; X and Y are independently selected from Cl, Br and I, b) reacting said reaction mixture with a suitable halogenated compound in a solvent to form a Grignard reagent, c) reacting said Grignard reagent with a suitable linear, branched or cyclic carbonate to obtain a compound of formula (IV) wherein A is a linear, branched or cyclic C1-C6 alkyl group, and preferably a methyl group, and then further reacting the compound of formula (IV) in a known manner to obtain a compound of formula (I) and optionally salt formation. |
