(4S,1'E)-4-(3'-hydroxy-2'-methylprop-1'-enyl)azetidin-2-one

(4S,1'E)-1-(tert-butyldimethylsilyl)-4-(3'-tert-butyldimethylsilyloxy-2'-methylprop-1'-enyl)azetidin-2-one

(3S,4S,5S,6R,1'R,2'E)-3-(4'-hydroxy-3'-methyl-1'-propanoylaminobut-2'-enyl)-4-hydroxy-3,5-dimethyl-6-prop-2''-enyltetrahydropyran-2-one

(3S,4R,2'R,3'R,1''E)-3-(3'-hydroxy-2'-methyl-1'-oxohex-5'-enyl)-4-(3''-hydroxy-2''-methylprop-1''-enyl)-3-methyl-1-oxopropylazetidin-2-one

(3S,4R,2'R,3'R,1''E)-3-(3'-tert-butyldimethylsilyloxy-2'-methyl-1'-oxohex-5'-enyl)-4-(3''-tert-butyldimethylsilyloxy-2''-methylprop-1''-enyl)-3-methylazetidin-2-one