Synthesis of l-Pyranosides from 5-Enopyranosides by Diastereoselective Hydroboration/Oxidation

Improved synthesis of L-pyranosides utilizing diastereoselective hydroboration/oxidation of 5-enopyranosides was investigated. A unique phenomenon in the diastereoselectivity of the hydroboration was incidentally found. The method was successfully applied to the synthesis of L-iduronic acid.