Toluene-4-sulfonic acid (R)-1-[(3aR,5S,6R,6aR)-6-(4-methoxy-benzyloxy)-2,2-dimethyl-tetrahydro-furo[2,3-d][1,3]dioxol-5-yl]-ethyl ester

(3aR,5R,6R,6aR)-6-(4-methoxybenzyloxy)-2,2-dimethyl-5-vinyltetrahydrofuro[2,3-d][1,3]dioxole