Hydroxy-, Methoxymercuration and Lewis Acid Catalyzed Formyloxylation of Methyl Linoleate

✍ Scribed by Lucas, T. ;Schäfer, H. J.

• Book ID: 102932497
• Publisher: John Wiley and Sons
• Year: 1991
• Weight: 536 KB
• Volume: 93
• Category: Article
• ISSN: 0931-5985
• DOI: 10.1002/lipi.19910930302

✦ Synopsis

Methyl linoleate (1) reacts by hydroxymercuration-demercuration to methyl hydroxyoctadecenoates (2) of the ricinolic acid type and tetrahydrofurans 4,5. Good yields of 4 , 5 are favored by high concentrations of 1 and reagents and reflux temperature. Methyl ricinolate cyclizes in an analogous reaction nearly quantitatively to 4 with a high diastereoselectivity in favor of the syn-isomer. The methoxymercuration-demercuration leads to mono-and dimethoxy adducts. Mercury(I1)acetate can be substituted for nontoxic electrophiles. 1 affords in formic acid with BF,-etherate or HBF, as Lewis acids the mono-and diformiates in a ratio of 1 : I and 77% yield. In contrast to the oxymercuration, however, this addition is fairly regiounselective.

I . I n t r o d u c t i o n

The oxymercuration of olefins has been studied intensively since its exploration by Hofiann and Sand' in 1900.