ethyl (S)-2-[N-tosyl-(R)-prolyloxy]-2-[6-cyano-1,1-(ethylenedioxy)-5-oxo-1,2,3,5-tetrahydroindolizin-7-yl]butanoate

1,1-ethylenedioxy-5-oxo-(5'-ethyl-2'H,5'H,6'H-6-oxopyran)-[3',4',f]-Δ6(8)-tetrahydroindolizine

(S)-α-Ethyl-1,1-(ethylenedioxy)-α-hydroxy-6-(hydroxymethyl)-N-[(R)-1-phenylethyl]-5-oxo-1,2,3,5-tetrahydroindolizine-7-acetamide

ethyl 2-[N-tosyl-(R)-prolyloxy]-2-[6-cyano-1,1-(ethylenedioxy)-5-oxo-1,2,3,5-tetrahydroindolizin-7-yl]acetate

propyl (4S)-4-ethyl-3,4-dihydroxy-8-methoxy-1,3-dihydropyrano[3,4-c]pyridine-6-carboxylate