(3-tert-butoxycarbonylamino-4-hydroxy-1-methyl-butyl)-carbamic acid tert-butyl ester

(4S,6R)-6-(tert-Butyl-diphenyl-silanyloxymethyl)-6-methyl-5,6-dihydro-4H-pyrimidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester

(R)-Δ2-5-formyl-5-methyl-3-pyrazolinecarboxylic acid ethyl ester

(4R,6R)-4-(tert-Butyl-diphenyl-silanyloxymethyl)-4-methyl-2,2-dioxo-2λ6-[1,2,3]oxathiazinane-6-carboxylic acid ethyl ester

(4R,6R)-4-(tert-Butyl-diphenyl-silanyloxymethyl)-4-methyl-2,2-dioxo-2λ6-[1,2,3]oxathiazinane-3,6-dicarboxylic acid 3-tert-butyl ester 6-ethyl ester