(2E,4R,5S,7S,10S,11R,12S,14R)-5,11,15-tris(tert-butyldimethylsilyloxy)-4,10,12,14-tetramethyl-1-(trityloxy)pentadec-2-en-8-yn-7-ol

ethyl (4R,5S,2E)-5,7-bis(tert-butyldimethylsilyloxy)-4-methylhept-2-enoate