121775-95-9Relevant academic research and scientific papers
Total regio- and diastereocontrol in the aldol reactions of dienolborinates
Ramachandran, P. Veeraraghavan,Nicponski, Daniel,Kim, Bomi
, p. 1398 - 1401 (2013)
It is reported that appropriate dienolborinates can provide access to both diastereomers of 2-(hydroxymethyl)but-3-enoates through exclusive α-regiocontrol in a non-vinylogous pathway. Contrary to previous reports in which dialkylchloroboranes failed to enolize propanoates, acidity-enhanced but-3-enoates readily undergo enolization, offering unprecedented control over the formation of these valuable synthons. The first example of an aldol reaction in the presence of a phosphine-borane adduct is also reported.
Dienediolates from Unsaturated Carboxylic Acids. Reaction with para-Substituted Benzaldehydes. Electronic Effects on Regioselectivity
Parra, Margarita,Mestres, Ramon,Aparicio, Domitila,Durana, Nieves,Rubiales, Gloria
, p. 327 - 332 (2007/10/02)
Regioselectivity α/γ ratios for addition of the lithium dienediolate of crotonic acid to para-substituted benzaldehydes are subject to small electronic effects when reactions are carried out at low temperature, but strong influence by substituents is observed on heating for 1 h at 60 deg C.A linear correlation is then found between regiochemical ratios and ?p parameters.Stereoselectivity RR/RS ratios (33:66 to 43:57) for α-adducts obtained in the cold do not depend on the substituents.
