The synthesis of C-13 labeled vitamin E, (12'a,13'-13C)all-rac-.ALPHA.-tocopherol.
作者:SHIRO URANO、SHUNICHIRO NAKANO、MITSUYOSHI MATSUO
DOI:10.1248/cpb.33.1266
日期:——
[12'a, 13'-13C] all-rac-α-Tocopherol (1) was synthesized from [1, 3-13C] acetone. The condensation of 6-methoxymethoxy-2, 5, 7, 8-tetramethyl-2-[(E)-4-methyl-5-(thiazolin-2-yl) thio-3-penten-1-yl] chroman (8) with [7a, 8-13C] geranyl bromide (7), which was prepared by the coupling of (E)-(6-benzoyloxy-4-methyl-4-hexen-1-yl) triphenylphosphonium bromide (5) with [1, 3-13C] acetone, followed by bromination, afforded 6-methoxymethoxy-2, 5, 7, 8-tetramethyl-2-[12a, 13-13C] (3E, 7E, 11E) 4, 8, 12-trimethyl-5-(thiazolin-2-yl) thio-3, 7, 11-tridecatrien-1-yl] chroman (9). After desulfurization and reduction of 9, the reaction product was converted to [12'a, 13'-13C] all-rac-α-tocopherol (1) by the use of methanolic hydrogen chloride. The overall yield of 1 was 33% on the basis of [1, 3-13C] acetone.
[12'a, 13'-13C]全反式-α-生育酚(1)由[1, 3-13C]丙酮合成。6-甲氧甲氧基-2, 5, 7, 8-四甲基-2-[(E)-4-甲基-5-(噻唑啉-2-基)硫代-3-戊烯-1-基]色满(8)与[7a, 8-13C]香叶基溴(7)缩合,后者由(E)-(6-苯甲酰氧基-4-甲基-4-己烯-1-基)三苯基膦溴化物(5)与[1, 3-13C]丙酮耦合,随后溴化得到6-甲氧甲氧基-2, 5, 7, 8-四甲基-2-[12a, 13-13C] (3E, 7E, 11E) 4, 8, 12-三甲基-5-(噻唑啉-2-基)硫代-3, 7, 11-十三碳三烯-1-基]色满(9)。去除硫并还原9后,通过使用甲醇氢氯酸将反应产物转化为[12'a, 13'-13C]全反式-α-生育酚(1)。基于[1, 3-13C]丙酮,1的总产率为33%。