2-(tert-butyldimethylsiloxymethyl)-4-hydroxymethyl-1,3,3-trimethyl-cyclohexa-1,4-diene

(5S)-7-(tert-butyldimethylsiloxymethyl)-1,3-dioxa-2-oxo-6,6,8-trimethyl-spiro[4,5]dec-7-ene