Stereoselective synthesis of syn,syn- and syn,anti-1,3,5-triols via intramolecular hydrosilylation of substituted pent-3-en-1,5-diols.

A stereoselective method for synthesis of syn,syn- and syn,anti-1,3,5-triols based on a double allylboration-intramolecular hydrosilylation sequence has been developed. The 1,3-syn stereocontrol is achieved in the intramolecular hydrosilylation of monoprotected (Z)-1,5-syn-diols and (E)-1,5-anti-diols with 87:13 to 95:5 and 86:14 to 88:12 diastereomeric ratios, respectively, by using 0.5 mol % of Karstedt's catalyst in toluene.