(1S,3R,5R,6R,7R)-6,7-Bis-benzyloxy-1-but-3-enyl-3-(tert-butyl-dimethyl-silanyloxymethyl)-5-(tert-butyl-diphenyl-silanyloxymethyl)-2,8-dioxa-bicyclo[3.2.1]octan-4-one

(1S,3R,4S,5R,6R,7R)-6,7-Bis-benzyloxy-1-but-3-enyl-3-(tert-butyl-dimethyl-silanyloxymethyl)-5-(tert-butyl-diphenyl-silanyloxymethyl)-4-vinyl-2,8-dioxa-bicyclo[3.2.1]octan-4-ol