210487-22-2Relevant academic research and scientific papers
Preparation of Biologically Active Hydroxyketones and Analogues system through Masked Lithium ω-Enolates Generated by a Naphthalene-catalyzed lithiation
Alonso, Emma,Ramon, Diego J.,Yus, Miguel
, p. 56 - 61 (2007/10/03)
The reaction of ω-chloroacetal 1 with lithium and a catalytic amount of naphthalene (4 molpercent) in THF at -78 deg C leads to intermediate 3, which by reaction with different electrophiles tCHO, PhCHO, Et2CO, (CH2)5CO, CH3(CH2)nCON(OMe)Me (n = 5, 6)> and final hydrolysis with water affords functionalized acetals 2.Acidic treatment of compounds 2 provides functionalized aldehydes 4.Titanium (IV) mediated chemoselective addition of n-butyllithium to ketoaldehydes 4f,g affords after hydrolysis, hydroksyketones 5f, g.Naphthalene-catalyzed lithiation of chloroacetal 6 followed by reaction with n-butanal yields, after hydrolysis, hydroxyacetal 7, which after transformation into the THP-protected dithiane 9 gives hydroxyketone 10, after successive deprotonation, alkylation and final full deprotection.Hydroxyketones 5g and 10 are interesting natural products. - Key words: hydroxyketones; lithiation; naphthalene; natural products
