Fatty acids, Part 30 The formation of 1,4-epoxides from two series of trihydroxystearic acids by acid-catalysed cyclisation

✍ Scribed by G.G. Abbot; F.D. Gunstone

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 497 KB
• Volume: 7
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(71)90006-5

✦ Synopsis

Ricinoleic acid can give four diastereoisomeric 9,10,12-trihydroxystearic acids. Each of these, when treated with acidic methanol, gives, mainly or entirely, one isomer of methyl 9,12-epoxy-10-hydroxystearate from which the corresponding 10-methoxy and 10-oxo esters are prepared. Structural identification is based mainly on mass spectroscopy. 9-Hydroxyoctadec-cis-12-enoic acid gives a similar series of 9,12,13-trihydroxystearic acids which yield 9,12-epoxy-13-hydroxy (methoxy, oxo)stearates. The mechanism and stereochemistry of the cyclisation reaction are discussed. * Part 29: Chem. Phys. Lipds 7 (1971) 121. ** These mixtures of two diastereoisomers are described throughout this paper by the prefix erythro or threo as appropriate.