3-[(6S,7R)-7-(2-Hydroxy-ethyl)-6,7-dimethyl-1,4-dioxa-spiro[4.5]dec-6-yl]-propionic acid methyl ester

3-((6S,7R)-7-(2-((tert-butyldimethylsilyl)oxy)ethyl)-6,7-dimethyl-1,4-dioxaspiro[4.5]decan-6-yl)propanal

3-{(6S,7R)-7-[2-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-6,7-dimethyl-1,4-dioxa-spiro[4.5]dec-6-yl}-propionic acid methyl ester

(R)-5-[(S)-6-((6S,7R)-7-Carboxymethyl-6,7-dimethyl-1,4-dioxa-spiro[4.5]dec-6-yl)-2-methyl-4-oxo-hexyl]-2,2-dimethyl-oxazolidine-3-carboxylic acid benzyl ester

(R)-5-((S)-3-Benzenesulfonyl-6-{(6S,7R)-7-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-6,7-dimethyl-1,4-dioxa-spiro[4.5]dec-6-yl}-2-methyl-4-oxo-hexyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid benzyl ester