2'-O-(8-Hydroxy-2,6-dimethyl-2(E),6(E)-octadienoyl)-dihydropenstemide, a new iridoid glycoside from Penstemon...

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.