Acetic acid (1S,4R,4aS,5S,6S,7R,8aR)-6,7-diacetoxy-8a-(tert-butyl-dimethyl-silanyloxymethyl)-8-oxo-1,4,4a,5,6,7,8,8a-octahydro-1,4-methano-naphthalen-5-yl ester

Acetic acid (1R,2S,6R)-4-hydroxymethyl-5-oxo-7-oxa-bicyclo[4.1.0]hept-3-en-2-yl ester

Acetic acid (1R,2S,5R,6S)-5-hydroxy-4-hydroxymethyl-7-oxa-bicyclo[4.1.0]hept-3-en-2-yl ester

(1R,5R,6R)-3-(tert-Butyl-dimethyl-silanyloxymethyl)-5-hydroxy-7-oxa-bicyclo[4.1.0]hept-3-en-2-one

(1R,5S,6R)-3-(tert-Butyl-dimethyl-silanyloxymethyl)-5-hydroxy-7-oxa-bicyclo[4.1.0]hept-3-en-2-one