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US 4,269,772 AGranted
Synthesis of thienamycin via trans-3-carboxymethylene-4-carboxy-5-methyl-.DELTA..sup.2 -isoxazoline
AssigneeMerck & Co., Inc.
InventorsDavid G. Melillo, Kenneth M. Ryan
Life of this patent
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Abstract
Disclosed is a process for the stereocontrolled total synthesis of thienamycin, which synthesis proceeds via intermediate II: ##STR1## wherein R.sup.5 and R.sup.6 are removable protecting groups.
Claims1
A process for preparing:
- ##STR22## and its pharmaceutically acceptable salts which comprise the cycloaddition of:
- ##STR23## with
- CH.sub.3 CH.dbd.CHCOOR.sup.6
- to form:
- ##STR24## followed by reduction to yield:
- ##STR25## followed by cyclization and deblocking to yield:
- ##STR26## followed by alcoholysis with R.sup.1 OH to form:
- ##STR27## followed by cyclizing to form:
- ##STR28## followed by carboxyl-deprotecting, activating and treating with (R.sup.3 O.sub.2 CCH.sub.2 CO.sub.2).sub.2 Mg to form:
- ##STR29## followed by deprotecting, diazotizing, and cyclizing to form:
- ##STR30## followed by activating, treating with HSCH.sub.2 CH.sub.2 NHR.sup.4 and deprotecting wherein R.sup.1, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are removable protecting groups.
8 more elements
Dependencies are inferred from the claim text.