Certain intermediates for the preparation of neuinic acid derivatives

US5256811A · kind A · utility

Assignee

• British Biotechnology Ltd. · GB

Inventors

• Richard Simon Todd · Calumet City, US
• Maxwell M. Reeve · Guilford, US

Key dates

• Filing date: Dec 6, 1991
• Grant date: Oct 26, 1993
• Expiry date: Dec 6, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/55
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

compounds of formula I ##STR1## wherein R.sup.1 represents a C.sub.1-8 alkyl, C.sub.2-8 alkenyl, C.sub.2-8 alkynyl, C.sub.3-8 cycloalkyl(C.sub.1-8)alkyl, C.sub.1-8 hydroxyalkyl, C.sub.1-8 alkylthio, phenyl or substituted phenyl; PA0 R.sup.3 represents a C.sub.1-8 alkyl, C.sub.2-8 alkenyl, C.sub.2-8 alkynyl, CO2(C.sub.1-8)alkyl, CO.sub.2 (C.sub.2-8) alkenyl, C.sub.1-8 alkylthio, (C.sub.1-2)alkyl CO.sub.2 (C.sub.1-8) alkyl or C.sub.1-8 aldehydroalkyl where the aldehyde function is protected by a suitable protecting group (for example, an acetal such as a dimethyl acetal); PA0 R.sup.4 represents a hydrogen atom, C.sub.1-8 alkyl or C.sub.2-8 alkenyl; PA0 Z represents a group (CH.sub.2).sub.n or a branched alkyl chain; PA0 n is 1 to 8; PA0 and each of a, b and c is independently a single or a double bond; PA0 can be prepared relatively easily and in good xxx at room temperature by reacting a compound of general formula II ##STR2## wherein R.sup.2, R.sup.3, R.sup.4, Z, a, b and c are as define din general formula I; with a compound of general formula III EQU CHI.sub.2 R.sup.1 (III) PA0 wherein R.sup.1 is as defined in general formula I; PA0 in the presence of metal ions such as chromium …