A Formal Total Synthesis of (+)-Methyl Trachyloban-18-oate and (+)-Methyl 16-Oxo-17-norkauran-18-oate: Regio- and Diastereoselective Preparation of Methyl (13S)-13-Hydroxyisoatisiren-18-oate from (?)-Abietic Acid
作者:Marco Berettoni、Giovanna De Chiara、Tommaso Iacoangeli、Paola Lo Surdo、Rinaldo Marini Bettolo、Lorenzo Montagnini Di Mirabello、Luca Nicolini、Rita Scarpelli
DOI:10.1002/hlca.19960790724
日期:1996.10.30
A novel preparation of methyl (13S)-13-hydroxyisoatisiren-18-oate (4), a key-intermediate in a synthesis of (+)-methyl trachyloban-18-oate ((+)-1), from (−)-abietic acid, is described. Since (−)-1 has been previously converted into (−)-methyl 16-oxo-17-norkauran-18-oate ((−)-16), our preparation of 4 constitutes also a formal total synthesis, from (−)-abietic acid, of (+)-16. Key steps in this approach
一种新的(13 S)-13-羟基异戊二烯-18酸酯(4)的新制备方法,是从(-)合成(+)-甲基trachyloban-18酸酯((+)- 1)的关键中间体。描述了-松香酸。由于(-)- 1已预先转化为(-)-甲基16-oxo-17-norkauran-18-oate((-)- 16),因此我们制备的4也构成了由(-)形成的正式总合成物-松香酸,(+)- 16。该方法的关键步骤是将烯丙基光敏加到罗汉松8(14)-en-13-one(5)上,以及将内-甲苯-4-磺酸酯11转化为外-苯甲酸酯12b。。