Choi Seyoung, Koo Sangho
Department of Chemistry, Myong Ji University, Yongin, Kyunggi-Do 449-728, Korea.
J Org Chem. 2005 Apr 15;70(8):3328-31. doi: 10.1021/jo050101l.
Three keto-carotenoids were prepared by the oxidation of the stable C(40) trisulfone 6, which has been used as the key compound in our beta-carotene synthesis. The first allylic oxidation to the unsaturated ketone and the second oxidation to the alpha-hydroxyketone produced the C(40) trisulfones 7 and 10, respectively. The Ramberg-Backlund reaction of the oxidized C(40) trisulfone was efficiently effected by the use of a mild base, NaOMe, in the presence of CCl(4) as a halogenating agent to give the C(40) disulfones 8 and 11. Base-promoted dehydrosulfonation reaction of the disulfone compounds produced the fully conjugated polyenes of canthaxanthin (1), astaxanthin (2), and astacene (3).
通过稳定的C(40)三砜6的氧化反应制备了三种酮类类胡萝卜素，该三砜6已被用作我们β-胡萝卜素合成中的关键化合物。第一次烯丙基氧化生成不饱和酮，第二次氧化生成α-羟基酮，分别得到C(40)三砜7和10。在作为卤化剂的CCl(4)存在下，使用温和的碱NaOMe有效地实现了氧化的C(40)三砜的Ramberg-Backlund反应，得到C(40)二砜8和11。二砜化合物的碱促进脱磺化反应产生了角黄素(1)、虾青素(2)和虾红素(3)的完全共轭多烯。
