Preparation of (1R,4S)-4-hydroxy-1,2,2-trimethylcyclopentyl methyl ketone and derivatives and stereoisomers of this compound

US6111125A · kind A · utility

Assignee

• BASF SE

Inventors

• Michael Sasha John · Larchmont, US
• Udo Rheude · Otterstadt, DE
• Joachim Paust · Schifferstadt, DE
• Joachim Meyer · Frankenthal (Pfalz), DE

Key dates

• Filing date: Mar 3, 1995
• Grant date: Aug 29, 2000
• Expiry date: Mar 3, 2015

Classification

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

Abstract

A process for preparing 4-hydroxy-1,2,2-trimethylcyclopentyl methyl ketones of the general formula I, in particular of the (1R,4S)-4-hydroxy-1,2,2-trimethylcyclopentyl methyl ketone of the formula Ia ##STR1## which is required for preparing the red dye capsorubin which is in demand, starts from 2,2,6-trimethylcyclohexanones of the general formula II ##STR2## where R is hydrogen or a protective group, via the novel intermediates of the general formulae V and VI ##STR3## by diastereoselective epoxidation and reaction of the resulting 7-oxabicyclo[4.1.0]heptanes of the general formula VIII ##STR4## with Lewis acids and, where appropriate, removal of the protective group. Also claimed are the novel intermediates of the formula V and their (1S) and (1R) isomers and those of the formula VIII as well as their (1R,3S,6S), (1S,3S,6R) and (1R,3R,6S) isomers.