| 摘要 |
There is provided a process for the preparation of a compound of formula (7) wherein R1 represents an alkyl group; R2 represents an aryl group; R3 represents hydrogen, a protecting group or an alkyl group; and R4 represents hydrogen, a protecting group or a SO2R5 group where R5 is an alkyl group, which comprises a) hydroxylating a compound of formula (1) wherein Y represents a halo group; P1 represents hydrogen or a protecting group, and W represents═O or—OP2, in which P2 represents hydrogen or a protecting group, to give a compound of formula (2), b) oxidixing the compound of formula (2) to give a compound of formula (3), c) coupling the compound of formula (3) with a compound of formula (4), wherein R3 represents a protecting group or an alkyl group; R4 represents a protecting group or a SO2R5 group where R5 is an alkyl group; and R6 represents (PR7R8)+X−or P(═O)R7R8 in which X is an anion and R7 and R8 each independently is an alkyl, aryl. |
