(1R,3S)-3-(tert-Butyl-dimethyl-silanyloxymethyl)-8-hydroxy-1-hydroxymethyl-5,7-dimethoxy-6-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester

(1R,3S)-8-Allyloxy-1-allyloxymethyl-3-(tert-butyl-dimethyl-silanyloxymethyl)-5,7-dimethoxy-6-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester

(1R,3S)-8-Allyloxy-1-allyloxymethyl-3-(tert-butyl-dimethyl-silanyloxymethyl)-5,7-dimethoxy-6-methyl-1,2,3,4-tetrahydro-isoquinoline

(1R,3S,6R,11aS)-7-Allyloxy-6-allyloxymethyl-3-[5-(tert-butyl-dimethyl-silanyloxy)-2,4-dimethoxy-3-methyl-benzyl]-1-hydroxy-8,10-dimethoxy-9-methyl-4-oxo-1,3,4,6,11,11a-hexahydro-pyrazino[1,2-b]isoquinoline-2-carboxylic acid tert-butyl ester