Dithiaoctanediol → Z-(S)-[1-(2-{4-[3-(4-Chloro-phenyl)-allyloxy]-3-methoxy-phenyl}-ethylcarbamoyl)-2-methyl-propyl]-carbamic acid-tert.-butyl ester

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Reaction Steps

To (S)-[1-(2-{4-[3-(4-chloro-phenyl)-prop-2-ynyloxy]-3-methoxy-phenyl}ethylcarbamoyl)-2-methyl-propyl]-carbamic acid-tert.-butyl ester (18 g) in tetrahyrofuran (180 ml), Lindlar-catalyst (5%-Pd on CaSO4; 7.2 g), 3,6-dithia-1,8-octandiol (45 mg) and 2,2′-(ethylenedithio)-diethanol (45 mg) are added. The resulting mixture is shaken under a hydrogen atmosphere at room temperature and at normal pressure for 5 hours. It is then filtered and evaporated. The residue is purified by flash column chromatography on silica gel (ethyl acetate/hexane 1:2) and recrystallised (ethyl acetate/hexane). Z-(S)-[1-(2-{4-[3-(4-Chloro-phenyl)-allyloxy]-3-methoxy-phenyl}-ethylcarbamoyl)-2-methyl-propyl]-carbamic acid-tert.-butyl ester is obtained, m.p. 82-84° C.

Provenance & Evidence