# US 3,935,261 A · Cyclopentane derivatives

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- Number: US 3,935,261 A
- Document ID: US3935261A
- Status: Granted
- Kind: A
- Application number: 05/502,976
- Filed: 1974-09-03
- Granted: 1976-01-27
- Earliest claimed: 1970-01-23
- Assignees: May & Baker Limited
- Inventors: Michael Peter Lear Caton; Edward Charles John Coffee; Gordon Leonard Watkins
- Web page: https://patentgrep.com/patent/US3935261A

## CPC

- C07C 405/00: Compounds containing a five-membered ring having two side-chains in ortho position to each other, and having oxygen atoms directly attached to the ring in ortho position to one of the side-chains, one side-chain containing, not directly attached to the ring, a carbon atom having three bonds to hetero atoms with at the most one bond to halogen, and the other side-chain having oxygen atoms attached in gamma-position to the ring, e.g. prostaglandins {; Analogues or derivatives thereof}
- C07C 45/00: Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C 243/28: to hydrogen atoms or to carbon atoms of a saturated carbon skeleton
- C07F 9/5407: {Acyclic saturated phosphonium compounds}
- C07C 2601/08: the ring being saturated
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)

## Abstract

Cyclopentane derivatives of the prostaglandin type of the formula: ##SPC1## (wherein R.sup.1 represents hydrogen or lower alkyl, R.sup.2 represents alkyl of 1 to 10 carbon atoms, the symbols R.sup.3 are the same and represent hydrogen, lower alkyl, lower alkenyl, phenyl(lower)alkyl or lower alkanoyl, R.sup.4 represents a carboxy or alkoxycarbonyl group, or an amido group unsubstituted or substituted on the nitrogen atom, X represents vinylene, ethylene, epoxyethylene or cyclopropylene, and n represents an integer of 5 to 8), which possess pharmacological properties in particular the production of hypotension, bronchodilation, inhibition of gastric acid secretion and stimulation of uterine contraction are prepared by a new six-stage process involving initially the reaction of an enamine of a cyclopentanone with an aldehyde to form a 2-hydroxyalkyl-2-cyclopenten-1-one, reacting the cyclopentenone with a source of hydrogen cyanide to form a hydroxyalkyl-3-oxocyclopentane-carbonitrile, reducing the carbonitrile to a 3-hydroxy-2-hydroxyalkyl-cyclopentanecarbaldehyde, reacting the carbaldehyde with an alkanoylmethylenephosphorane to convert the formyl group to ------CH=CH --CO--R.sup.2, oxidising the terminal hydroxymethyl group in the 2-position substituent to carboxy and the ring hydroxy group to oxo, and reducing the two oxo groups in the resulting cyclopentanonealkanoic acid to yield a 2-hydroxy-5-(3-hydroxyalkenyl)cyclopentyl-alkanoic acid, and optionally converting the product into another compound of the foregoing formula.

## Claims

### Claim 1

A cyclopentane compound of the formula: ##SPC7##
wherein R.sup.1 represents a hydrogen atom or a lower alkyl group, R.sup.2 represents a straight- or branched-chain alkyl group of 1 to 10 carbon atoms, R.sup.3 represents a hydrogen atom or a lower alkyl, lower alkenyl, phenyl-(lower)alkyl and lower alkanoyl group, R.sup.4 represents a group of formula: ##EQU10## wherein R.sup.5, R.sup.6 and R.sup.7 each represents a hydrogen atom or a lower alkyl group, X represents a vinylene, ethylene, or cyclopropylene group, and n represents 5, 6, 7 or 8.

### Claim 2

N-Methyl-7-[2-hydroxy-5-(3-hydroxy-1-octenyl)cyclopentyl]-heptanoamide.

### Claim 3

7-[2-Hydroxy-5-(3-hydroxy-1-octenyl)cyclopentyl]heptanohydrazide.