(6S)-3-(Diethoxymethyl)-3a,6a-dihydro-5H,6H,3aH,6aH-oxolano[2,3-d]isoxazole-5,6-diol 5,6-Isopropylidenedioxyfuro[2,3-d]isoxazole-3-methanol derivative AIDS-096130 AIDS096130