The C-15/C-27 segment of venturicidine contains a 1,3,5,n-anti-methylated alkyl chain, which resembles syndiotactic polypropylene and should therefore favor an extended conformation. A synthetic scheme is presented, by which such structures are generated in a cycle of four steps per three stereogenic centers. This allowed the synthesis of the above mentioned venturicidine fragment in 15 steps from propionaldehyde.
Goettlich, Richard; Faecke, Thomas; Rolle, Ulrike, Journal of the Chemical Society. Perkin transactions II, 1996, # 10, p. 2059 - 2064
作者:Goettlich, Richard、Faecke, Thomas、Rolle, Ulrike、Hoffmann, Reinhard W.
DOI:——
日期:——
Stereoselective Synthesis of Alcohols, L. Stereoselective Synthesis of a C-15/C-27 Segment of the Venturicidines
作者:Reinhard W. Hoffmann、Ulrike Rolle、Richard Göttlich
DOI:10.1002/jlac.199619961104
日期:1996.11
Chain extension of an aldehyde by two “propionate” units has been attained by stereoselective allylboration with the chiral 1-methylbutenyl boronate 3 to give, e.g., the homoallylic alcohol 6, followed by a regioselective hydroboration/carbonylation procedure to give, e.g., the epimeric aldehydes 8. The latter were converted into the lactols 10, which equilibrated to the desired epimer. The lactols