5-(Benzyloxy)-4-isobutyl-3-(1-phenylethyl)-1,2,3-oxathiazinane 2,2-dioxide AIDS-150786 AIDS150786 Benzyl 4-isobutyl-2,2-dioxido-3-(1-phenylethyl)-1,2,3-oxathiazinan-5-yl ether NSC688895