[(5S,6R,7R,8S,10S)-8,10-Bis-benzyloxy-7-(4-methoxy-benzyloxymethyl)-2,2,7-trimethyl-1,3-dioxa-spiro[4.5]dec-6-yl]-methanol 以96%的产率得到(5S,6S,7R,8S,10S)-8,10-Bis-benzyloxy-7-(4-methoxy-benzyloxymethyl)-2,2,7-trimethyl-1,3-dioxa-spiro[4.5]decane-6-carbaldehyde