(1R,2E,6S,17R,18S)-17-Hydroxy-6,20,20-trimethyl-5,19,21-trioxabicyclo<16.3.0>henicos-2-en-4-on

(2R,3S,4R)-1-Benzyloxy-2-methoxymethoxy-hept-6-ene-3,4-diol