Stereoselective Synthesis of syn,syn- and syn,anti-1,3,5-Triols via Intramolecular Hydrosilylation of Substituted Pent-3-en-1,5-diols
摘要:
A stereoselective method for synthesis of syn,syn- and syn,anti-1,3,5-triols based on a double allylboration-intramolecular hydrosilylation sequence has been developed. The 1,3-syn stereocontrol is achieved in the intramolecular hydrosilylation of monoprotected (Z)-1,5-syn-diols and (E)-1,5-anti-diols with 87:13 to 95:5 and 86:14 to 88:12 diastereomeric ratios, respectively, by using 0.5 mol % of Karstedt's catalyst in toluene.
Stereoselective Synthesis of syn,syn- and syn,anti-1,3,5-Triols via Intramolecular Hydrosilylation of Substituted Pent-3-en-1,5-diols
摘要:
A stereoselective method for synthesis of syn,syn- and syn,anti-1,3,5-triols based on a double allylboration-intramolecular hydrosilylation sequence has been developed. The 1,3-syn stereocontrol is achieved in the intramolecular hydrosilylation of monoprotected (Z)-1,5-syn-diols and (E)-1,5-anti-diols with 87:13 to 95:5 and 86:14 to 88:12 diastereomeric ratios, respectively, by using 0.5 mol % of Karstedt's catalyst in toluene.
Concerning the Selective Protection of (<i>Z</i>)-1,5-<i>syn</i>-Ene-diols and (<i>E</i>)-1,5-<i>anti</i>-Ene-diols as Allylic Triethylsilyl Ethers
作者:Jacqueline D. Hicks、Chan Woo Huh、Ashley D. Legg、William R. Roush
DOI:10.1021/ol702588h
日期:2007.12.1
Treatment of unsaturated 1,5-diols 2 with TES-CI (1.1 equiv), imidazole, and catalytic DMAP in 1:1 CH2Cl2-DMF at -78 degrees C effects selective silylation of the allylic alcohol with > 95:5 chemoselectivity when the allylic and homoallylic alcohols are in similar steric environments.