作者:Aisling O’Byrne、Steven O’Reilly、Catherine Tighe、Paul Evans、Laura Ciuffini、M. Gabriella Santoro
DOI:10.1016/j.tetlet.2012.08.101
日期:2012.10
A stereocontrolled synthesis of the marine natural products (+)-bromoxone (1) and (+)-4-acetylbromoxone (2) is reported. The sequence features the enzymatic kinetic resolution of 4-hydroxycyclohexenone (6) via its S-benzyl adduct. Thereafter, a base-mediated elimination–silylation generated an optically active (−)-4S-4-tert-butyldimethylsilyoxycyclohexenone (5), which then underwent diastereoselective
bromoxone( -海洋天然产物(+)的立体控制合成1 4- acetylbromoxone( - )和(+)2被报告)。该序列具有4-羟基环己烯酮(6)通过其S-苄基加合物的酶促动力学拆分特征。此后,碱介导的消除-甲硅烷基化反应生成了旋光性(-)-4 S -4-叔丁基二甲基甲硅烷氧基环己烯酮(5),然后进行非对映选择性环氧化。Saegusa-Ito氧化能够形成相应的α,β-不饱和酮13。溴化消除并随后除去硅保护基,得到(+)-溴酮(1),将其转化为(+)-(4 S,5 R,6 R)-4-乙酰氧基-2-溴-5,6-环氧环己基-2-烯酮(2)[(+)-4-乙酰基溴酮]。使用萤光素酶基因报告基因测定法,ED 50对NFκB的抑制作用为9μM。