Titanocene(II)-Promoted Olefination of ω,ω-Bis(phenylthio)alkyl Alkanoates. A New Method for the Preparation of ω-Hydroxy Ketones
摘要:
Intramolecular olefination of esters having a thioacetal moiety was studied. The treatment of omega,omega-bis(phenylthio)alkyl alkanoates with Cp2Ti[P(OEt)(3)](2) and the following hydrolysis gave omega-hydroxy ketones in good yields. (C) 2000 Elsevier Science Ltd. All rights reserved.
Stereodivergent Diversity Oriented Synthesis of Piperidine Alkaloids
作者:Louis V. Adriaenssens、Carolyn A. Austin、Mairi Gibson、David Smith、Richard C. Hartley
DOI:10.1002/ejoc.200600744
日期:2006.11
synthesis of 2-substituted piperidines and rapid access to multiple cyclic imines using solid phase synthesis (SPS). The Schrock carbenes, generated by reduction of thioacetals, convert resin-bound esters into enol ethers. Treatment with acid releases amino ketones that are cyclized with TMSCl to give iminium salts. Reduction introduces a chiral centre at C-2, whose absolutestereochemistry is determined
Titanocene(II)-Promoted Olefination of ω,ω-Bis(phenylthio)alkyl Alkanoates. A New Method for the Preparation of ω-Hydroxy Ketones
作者:Md.Abdur Rahim、Tooru Fujiwara、Takeshi Takeda
DOI:10.1016/s0040-4020(99)01091-1
日期:2000.1
Intramolecular olefination of esters having a thioacetal moiety was studied. The treatment of omega,omega-bis(phenylthio)alkyl alkanoates with Cp2Ti[P(OEt)(3)](2) and the following hydrolysis gave omega-hydroxy ketones in good yields. (C) 2000 Elsevier Science Ltd. All rights reserved.
Controlling neighbouring group participation from thioacetals
作者:Mairi Gibson、Jonathan M. Goodman、Louis J. Farrugia、Richard C. Hartley
DOI:10.1016/s0040-4039(03)00440-4
日期:2003.3
from 2-(3′-hydroxypropyl)-1,3-dithiane with thionyl chloride rearranges to 2-(3′-chloropropyl)-1,3-dithiane. Azide ion displacement of the primary alkyl chloride is then faster than [1.4] sulfanyl participation from the thioacetal. An α-chlorosulfide derived from diphenyldithioacetal does not rearrange but undergoes direct displacement to give an α-azidosulfide.