(4aR,7S)-4-[15-(allyloxycarbonyl)pentadecyloxycarbonyl]-1,2,4a,5,6,7-hexahydro-7-(2-hydroxyethyl)-1-oxo-3-[(4R)-4-(tert-butyldimethylsiloxypentyl)]-pyrrolo[1,2-c]-pyrimidine