(2R,3S,4S,5R,6R)-2-(acetoxymethyl)-6-[[(6S,9S)-2,2,6-trimethyl-4,7-dioxo-9-[(phenylthio)carbonyl]-3-oxa-11-thia-5,8-diazatetradecan-14-yl]oxy]tetrahydro-2H-pyran-3,4,5-triyl triacetate