# US 4,400,323 A · 3-[1-Hydroxyethyl]-4-carboxymethyl-azetidin-2-one

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- Number: US 4,400,323 A
- Document ID: US4400323A
- Status: Granted
- Kind: A
- Application number: 06/226,996
- Filed: 1981-01-21
- Granted: 1983-08-23
- Earliest claimed: 1979-07-23
- Assignees: Merck & Co., Inc.
- Inventors: Burton G. Christensen; Ronald W. Ratcliffe; Thomas N. Salzmann
- Web page: https://patentgrep.com/patent/US4400323A

## CPC

- C07D 205/08: with one oxygen atom directly attached in position 2, e.g. beta-lactams
- C07D 477/04: by forming the ring or condensed ring systems
- C07D 477/10: with hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached in position 4, and with a carbon atom having three bonds to hetero atoms with at the most one bond to halogen, e.g. an ester or nitrile radical, directly attached in position 2
- C07F 7/10: containing nitrogen {having a Si-N linkage}
- Y02P 20/55: Design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

In a process for the total synthesis of thienamycin from L-aspartic acid via intermediate III: ##STR1## there is disclosed a process for preparing III via ##STR2## wherein R is a protecting group.

## Claims

### Claim 1

The cis and trans isomers of a compound having the structure: ##STR48## wherein R is a readily removable blocking group selected from the group consisting of trialkylsilyl wherein the alkyl moieties have 1-6 carbon atoms each.

### Claim 2 (depends on 1)

A compound according to claim 1 wherein R is (t-butyl)dimethylsilyl.