| 摘要 |
The invention refers to the selective acylation of Rapamycin at the 42-position (I) with an acylating agent of the formula (II) wherein R4 and R5 are the same or different, individually the rest of an acetal, especially tetrahydropyran, or of a carbonate or the rest of a silyl ether or taken together are the rest of a boronate, an acetal or ketal. |
