(4R,5S)-4-((S)-1-Benzyloxy-3-phenyl-prop-2-ynyl)-5-ethyl-2,2-dimethyl-[1,3]dioxolane-4-carboxylic acid

[(4R,5S)-4-((S)-1-Benzyloxy-3-phenyl-prop-2-ynyl)-5-ethyl-2,2-dimethyl-[1,3]dioxolane-4-carbonyl]-carbamic acid tert-butyl ester