(1aS,2R,3aS,5R,7aR,7bR)-5-Bromomethyl-hexahydro-1,4,6-trioxa-cyclopropa[a]naphthalene-2,3a-dicarboxylic acid 2-tert-butyl ester 3a-ethyl ester

(2S,4aS,5R,8aR)-2-Bromomethyl-5-hydroxy-7-hydroxymethyl-4,4a,5,8-tetrahydro-benzo[1,3]dioxine-8a-carboxylic acid ethyl ester

(2R,4aR,5S,8aS)-2-Bromomethyl-5-hydroxy-4,4a,5,8-tetrahydro-benzo[1,3]dioxine-7,8a-dicarboxylic acid 7-tert-butyl ester 8a-ethyl ester

(1R,5R,6S)-3-(tert-Butyl-diphenyl-silanyloxymethyl)-1-hydroxy-5-methoxymethoxy-6-vinyloxymethyl-cyclohex-3-enecarboxylic acid ethyl ester