7-Oxabicyclo[4.1.0]hept-3-en-2-one, 5-hydroxy-3-(hydroxymethyl)-, (1.alpha.,5.alpha.,6.alpha.)-(.+-.)-, mixt. with (1.alpha.,5.beta.,6.alpha.)-(.+-.)-5-hydroxy-3-(hydroxymethyl)-7-oxabicyclo[4.1.0]hept-3-en-2-one NSC339560