Synthesis of 3‐Deoxy Glycals via Tandem Metathesis Sequences and Their Use in an Intermolecular Heck Arylation

Deoxy glycals can be synthesized from a mannitol‐derived C2‐symmetric diene diol by using the tandem RCM/isomerization approach. Incorporation of a ruthenium‐catalyzed dehydrogenative silylation step into the reaction sequence is possible. Thus, an orthogonally protected 3‐deoxy glycalresults via a tandem RCM/hydrosilylation/isomerization sequence. All ruthenium‐catalyzed steps of this tandem sequence occur under distinct conditions, allowing for the selective synthesis of the intermediates. The 3‐deoxy glycals obtained via this route undergo a regio‐ and stereoselective Heck reaction, as exemplified by the synthesis of a C‐aryl glycoside. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)