Patent GB-1468830-A (GB)
Title: Cyclopentane derivatives
IPC: C07C405/00
Filed: 1974-01-26
Abstract: 1468830 Cyclopentanone derivatives MAY & BAKER Ltd 24 Jan 1975 [26 Jan 1974] 03730/74 Headings C2C and C2P [Also in Division C3] The invention comprises cyclopentanone derivatives of the Formula I wherein R<SP>1</SP> is H or carboxylic acyl, and either (i) R<SP>2</SP> is -CR<SP>2</SP>R<SP>4</SP>R<SP>5</SP>, wherein R<SP>3</SP> and R<SP>4</SP> each are H or C 1-4  alkyl; and R<SP>5</SP> is H or C 1-10  alkyl, C 1-10  alkoxy, C 5-7  cycloalkyl, adamantyl or C 1-6  alkyl substituted by a C 1-6  alkoxy, C 5-7  cycloalkyl or adamantyl radical, or the group -CR<SP>3</SP>R<SP>4</SP>R<SP>5</SP> together forms a C 5-7  cycloalkyl or adamantyl group, X is trans-CH=CH- or CH 2 CH 2 - and Y is carbonyl or wherein R<SP>6</SP> is H or C 1-4  alkyl and R<SP>7</SP> is H, or when R<SP>1</SP> is carboxylic acyl, R<SP>7</SP> is H or carboxylic acyl, or else (ii) R<SP>2</SP> is -A-Z-R<SP>8</SP>, wherein A is C 1-12  alkylene, Z is a direct bond, O or S, and R<SP>8</SP> is aryl or heterocyclyl group which may be substituted by one or more substituents selected from halogen, C 1-6  alkyl, C 1-6  alkoxy and trihalomethyl; X is CH 2 CH 2  or trans CH=CH, Y is carbonyl or or (iii) R<SP>2</SP> is a group R<SP>8</SP> and X and Y are simultaneously -CH 2 CH 2 - and carbonyl or ethylene and respectively, and their preparation. The compounds of Formula I above wherein R<SP>1</SP> is H are prepared by hydrolysing compounds of the Formula V wherein the symbols R<SP>9</SP> are identical alkyl radicals or together form an ethylene linkage optionally substituted by identical alkyl groups on each carbon atom, and R<SP>10</SP> is H or when Y is wherein R<SP>6</SP> is alkyl and R<SP>7</SP> is H, the group -OR<SP>10</SP> optionally represents a protected hydroxy group and the OH group forming part of is then optionally in the form of a Grignard intermediate complex. The following intermediates and starting materials are prepared: compounds of Formula V above; 1 - chloro - 2 - oxo - 5 - phenylpentane; ethyl 2-(2-phenylethyl)hexanoate, and 1-chloro-3-phenoxyacetone. Dimethyl 2 - cyclohexyl - 2 - oxoethylphosphonate, dimethyl 2 - oxo - 4 - phenylbutylphosphonate, dimethyl 2 - oxo - 3 - phenylpropylphosphonate, dimethyl 2 - oxo - 3 - (2 - phenylethyl)heptylphosphonate and dimethyl 3-methyl-2-oxobutylphosphonate are prepared by reacting dimethyl methylphosphonate with ethyl cyclohexanecarboxylate, ethyl 3-phenylpropionate, ethyl phenylacetate, ethyl 2 - (2 - phenylethyl)- hexanoate and ethyl isobutyrate respectively in the presence of butyl lithium. Butyrylmethylenetriphenylphosphorone is prepared by reacting sodium carbonate with (2- oxopentyl)triphenylphosphonium chloride, obtained from triphenylphosphine and 1-chloropentan - 2 - one. (3 - Ethoxypropionyl)methylenetriphenylphosphorone, (4 - ethoxy - 2 - oxobutyl)- triphenylphosphonium chloride, (4 - phenylbutanoyl)methylenetriphenylphosphorane, (5- phenylpentanoyl)triphenylphosphonium chloride, phenoxyacetylmethylenetriphenylphosphorane and (2 - oxo - 3 - phenoxypropyl)triphenylphosphonium chloride are prepared in a similar manner. Pharmaceutical compositions, suitable for oral rectal, nasal, vaginal and parenteral administration, contain the above cyclopentane derivatives and pharmaceutical carriers or coatings. The compounds possess pharmacological properties typical of the naturally occurring prostaglandins. British Patent Specification 1,398,073 is referred to.