| 摘要 |
<p>An increase in the diastereoselectivity resulting from the reaction of a phosphinic acid ester of the formula <CHEM> with the halo ester of the formula <CHEM> is achieved by carrying out the reaction in the presence of 4-methylmorpholine, diazabicyclooctane, quinuclidine, 1-methylpyrolidine, or cinchonidine. After removal of the R3 protecting group and fractional crystallization, the resulting desired diastereomeric pair can be resolved, and the desired isomer can be coupled to 4-substituted L-proline to give compounds possessing angiotensin converting enzyme inhibition activity. In particular, the process is useful in producing the antihypertensive agent fosinopril sodium in increased yields.</p> |
