(E)-3-[(2R,3S)-2-(2-Oxo-propyl)-tetrahydro-pyran-3-yloxy]-acrylic acid ethyl ester

((2R,3S,4aR,8aS)-3-Hydroxy-3-methyl-octahydro-pyrano[3,2-b]pyran-2-yl)-acetic acid ethyl ester