193957-75-4Relevant academic research and scientific papers
The effects of different ester and ketal protecting groups on the reactivity and selectivity of tartrate-derived silylketene acetals
Agganval, Varinder K.,Masters, Susannah J.,Adams, Harry,Spey, Sharon E.,Brown, George R.,Foubister, Alan J.
, p. 155 - 162 (2007/10/03)
The reaction of tartrate-derived silylketene acetals and benzaldehyde has been investigated and the yields and diastereoselectivities have been found to be dependent upon the nature of the tartrate ester. Utilising the di-to7-butyl tartrate derivatives, high yields were achieved using a variety of aldehyde substrates. The reactions all proceeded with excellent levels of stereoselectivity (== 82:18); the sense of induction being dependent upon the choice of Lewis acid. BF3-OEt2 and TiCl3(OiPr) furnished complementary products in several cases and a model has been proposed to account for this observation.
Aldol reactions of ketal-protected tartrate ester enolates. Asymmetric syntheses and absolute stereochemical assignments of phospholipase A2 inhibitors cinatrin C1 and C3
Evans, David A.,Trotter, B. Wesley,Barrow, James C.
, p. 8779 - 8794 (2007/10/03)
An efficient approach to the syntheses of cinatrins C1 and C3 has been developed and used to establish the absolute configurations of these natural products. The construction of each molecule has been achieved in a five-step reaction sequence (overall yield 43% for cinatrin C1, 33% for cinatrin C3) from the di-tert-butyl ester of (R,R)-tartaric acid. The two contiguous, quaternary chiral centers in the cinatrin skeleton are constructed via a diastereoselective, titanium-mediated aldol coupling of a tartrate-derived silylketene acetal and an achiral α-ketoester. This bond construction proceeds with excellent diastereoselectivity for a variety of aldehyde and α-ketoester substrates.
