An expedient synthesis of (R)-(+)-umbelactone

✍ Scribed by Colin L. Gibson; Sheetal Handa

• Book ID: 103977485
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 172 KB
• Volume: 7
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/0957-4166(96)00144-9

✦ Synopsis

The synthesis of the naturally occurring 2(5H)-furanone (R)-(+)-umbelactone 1 in five steps and 26.2% overall yield from

The 2(5H)-furanone (R)-(+)-umbelactone 1 has been isolated from the alcoholic extracts of Memycelon umbelatum Brum. 1 The crude extracts of this plant have shown antiviral, antiamphetarnine and spasmolytic activity, 2 consequently, the synthesis of 1 has been the subject of synthetic interest. Thus, the synthesis of the racemic material has been reported 3 and two asymmetric syntheses4, 5 of (R)-(+)-I and a synthesis of the (S)-(-) enantiomer 4 have been described. However, the reported syntheses of (R)-(+)-I are not particularly efficient and have been achieved in seven steps and 4.4% overall yield from (R)-(+)-glutamic acid 4 or in nine steps and 8.7% overall yield 5 from 1,2-dichloroacetone using a Baker's yeast enantioselective reduction. In this communication we report a synthesis of 1 in five steps and in 26.2% overall yield, starting from the (S)-acid 2.