(R)-2-[(3S,4S)-3-[(R)-1-(tert-Butyldimethylsilyloxy)ethyl]-2-oxoazetidin-4-yl]propionic acid90776-58-2100 % similar Azetidon76855-69-158 % similar 4-[[(1,1-Dimethylethyl)dimethylsilyl]oxy]dihydro-2H-pyran-2,6(3H)-dione91424-40-733 % similar N-[(1,1-Dimethylethoxy)carbonyl]-O-(1,1-dimethylethyl)-L-threonine13734-40-232 % similar N-[(1,1-Dimethylethoxy)carbonyl]-L-alanyl-L-alanine27317-69-732 % similar N-[(1,1-Dimethylethoxy)carbonyl]-O-methyl-L-threonine48068-25-331 % similar O-(1,1-Dimethylethyl)-L-threonine4378-13-630 % similar