Total Synthesis of (−)-Denticulatins A and B Using Efficient Methods of Acyclic Stereocontrol.
作者:Ian Paterson、Michael V. Perkins
DOI:10.1016/0040-4020(95)01015-7
日期:1996.1
The totalsynthesis of (−)-denticulatin B (2) was achieved in 9 steps (20% yield), with 70% overall diastereoselectivity, starting from the ethyl ketone (R)-9. Most of the stereochemistry was introduced by substratebased control. Key steps include the boron-mediated aldol/reduction, 9 → 22, the titanium-mediated aldol coupling, 26 + 8 → 38, and the directed cyclisation, 35 → 2. Epimerisation at C10
Studies in polypropionate synthesis: stereoselective synthesis of (−)-denticulatins A and B
作者:Ian Paterson、Michael V. Perkins
DOI:10.1016/s0040-4039(00)77719-7
日期:1992.2
from the ethyl ketone (R)-8. Key steps are the novel boron-mediated aldol/reduction, 8 → 12, the titanium aldol couping, 6 + 5 → 18, and the HF-pyridine cyclisation, 20 → 2. Epimerisation at C10 in 20 led to ()-denticulatin A (1).
Enantioselective total synthesis of (−)-denticulatins A and B using a novel group-selective aldolization of a meso dialdehyde as a key step
作者:Jef De Brabander、Wolfgang Oppolzer
DOI:10.1016/s0040-4020(97)00617-0
日期:1997.7
The diastereoselective synthesis of (-)-denticulatin A (1a) was achieved for the first time in 9 steps (41% yield) based on a novel group-selective aldolization of a meso dialdehyde as a key step. The inherent chirality present in bornanesultam 4 was thus transmitted to the five stereocenters spanning C-4-C-8 in key intermediate 8. In addition, denticulatin B (1b) was obtained from the common intermediate 8 en route to denticulatin A in 10 steps and 35% overall yield. (C) 1997 Elsevier Science Ltd.