Unusual fragmentation of trimethylsilylated enols derived from m- and p-hydroxyacetophenones

✍ Scribed by Rupert Kraus; Gerhard Spiteller

• Book ID: 102557048
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 396 KB
• Volume: 24
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210241002

✦ Synopsis

When 4hydroxyacetophenone is treated with MSTFA the corresponding his-trimethylsilylated enol ether (la) is obtained. The m a s spectrum of la is characterized by a [M -11' base peak. Extensive deuteration experiments revealed that the hydrogen is mainly removed from a ring position, but originates also to some extent from the side chain (methylidene group) and even to a very small amount from the hydrogens of the methyl groups of the enolic trimethylsilyl group. A mechanism for this fragmentation behaviour is formulated.