Synthetic studies towards complex diterpenoids. Part 11. Stereochemically defined synthesis of the racemates of 1,2,3,4,4a,9a-hexahydro-7-methoxy-1-methylfluorene-1-carboxylic acid
作者:Subrata Ghosh、Rupak Dasgupta、Jyotirmoy Chakravarty、Usha Ranjan Ghatak
DOI:10.1039/p19800000804
日期:——
Two simple synthetic routes to 1,2,3,4-tetrahydro-7-methoxy-1 -methylfluorene-1 -carboxylic acid (1b), a potential intermediate towards gibberellins, and its stereochemically defined transformations to three racemates of 1,2,3,4,4a,9a- hexahydro-7-methoxy-1 -methylfluorene-1 -carboxylic acid (4b)–(6b) are described. Catalytic hydrogenation of (1 b) yields a mixture of (5b) and (6b) in a ratio of ca
两条简单的合成路线可合成1,2,3,4-四氢-7-甲氧基-1-甲基芴-1-羧酸(1b),是赤霉素的潜在中间体,其立体化学定义的转化为1,2,3的外消旋体,描述了3,4,4a,9a-六氢-7-甲氧基-1-甲基芴-1-羧酸(4b)-(6b)。(1b)的催化加氢产生(5b)和(6b)的混合物,其比例为约1∶1 。95∶5,而(1b)的锂-液氨还原得到的比例为(约)的(4b)和(6b)。23:77.提出了一种机制来解释(1b)和相关系统锂氨还原中的立体化学结果。