Biomimetic rearrangements of simplified labdane diterpenoids
作者:Jonathan H. George、Mark McArdle、Jack E. Baldwin、Robert M. Adlington
DOI:10.1016/j.tet.2010.05.052
日期:2010.8
Simplified ethyl-substituted labdanediterpenoids 14 and 19 have been synthesised from (+)-sclareolide (18). Biomimetic rearrangements of these compounds, involving stereospecific 1,2-alkyl and hydride shifts, have been carried out by treatment with a variety of Lewis and protic acids. Halimane compounds, such as 34 and simple dehydration products such as 3, 32 and 33 have been formed either selectively
The first syntheses of cytotoxicmarine arenarans A and B starting from commercial (−)-sclareol are reported. The oxocene ring of the target compound is formed via ring-closing metathesis, a process that depends on certain structural requirements. The trans-fused structure of the naturalproduct is confirmed by comparison with the cis-fused isomer, which was synthesized. This synthetic strategy is