2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex- 2-enone, (3R-(3alpha,4alpha,5alpha))-isomer
2-crotonyloxymethyl-(4r,5r,6r)-4,5,6-trihydroxycyclohex- 2-enone, (3r-(3alpha,4alpha,5alpha))-isomer