Enantioselective synthesis of β-hydroxy-α-methyl carbonyl compounds by aldol reaction
作者:Akira Ando、Takayuki Shioiri
DOI:10.1016/s0040-4020(01)81078-4
日期:——
The enantioselective aldolreactions of ketone lithium enolates with aldehydes mediated chiral lithium amides were extensively investigated. The chiral amino ethers 4a–4l and diamines 16a,b were prepared from α-amino acids. The reaction conditions and the substituent effects of chiral lithium amides were examined using 4a–4l and 16a,b in the aldolreaction of lithium enolate of 2,2-dimethyl-3-pentanone
Acyclic stereoselection. 15. Sequential aldol-claisen as a method for 1,5-stereoselection. Total synthesis of the vitamin-E side chain
作者:Clayton H. Heathcock、Esa T. Jarvi
DOI:10.1016/s0040-4039(00)88423-3
日期:1982.1
Alcohol1, the side chain of α-tocopherol, has been synthesized in a stereoselective route involving an aldol condensation-Claisen rearrangement sequence. The synthesis require 11 steps and produces1in 17% overall yield. A complementary sequence employing reagent14provides isomer18.
Aldol-additions t0eα- and β-alkoxy aldehydes: The effect of chelation on simple diastereoselectivity
作者:M.T. Reetz、K. Kesseler、A. Jung
DOI:10.1016/s0040-4020(01)98807-6
日期:——
reaction of enol silanes with chiralα- and β-alkoxyaldehydes constitutes the only presently known, general way to perform aldol additions with chelation-control (asymmetric induction 90%). If the enol silane is prochiral, the additional stereoselection (simple diastereoselectivity) is surprisingly good. This unusual effect has been traced to syn-type of complexation of the aldehyde function.
1,4-Stereoselection by sequential aldol addition–Claisen rearrangement. Stereostructure of the C<sub>30</sub>diol from Messel shale kerogen
作者:Clayton H. Heathcock、Bruce L. Finkelstein
DOI:10.1039/c39830000919
日期:——
Diastereoisomeric amides (9) and (10) are prepared by stereo selective aldol addition, followed by Claisen rearrangement; isomer (9) has been employed to synthesize hydrocarbon (14) and there by establish the stereostructure of the molecular fossil 13, 16-dimethyloctacosane-1,28-diol.