Diisopropyl crotylboronates

Diisopropyl crotylboronates, 1. These chiral crotylboranates are prepared in 98-99% ee from diisopropyl tartrate. 

Roush, W. R., Ando, K., Powers, D. B., Halterman, R. L., Palkowitz, A. D. Enantioselective synthesis using diisopropyl tartrate-modified (E)-and (Z)-crotylboronates reactions with achiral aldehydes. Tetrahedron Lett. 1988, 29, 5579-5582. 

Allylboronate 196 is prepared from the reaction of allyl magnesium bromide with trimethylborate followed by esterification with diisopropyl tartrate (DIPT) in the presence of MgS04 (Eq. (11.13)) [116]. In analogous fashion, the (E)- and (Z)-crotylboronates 219 and 213 are prepared [139] in high isomeric purity (>98%) from ( )- and (Z)-2-butene by way of the (E)- and (Z)-crotylpotassium... 

This reaction was first reported by Roush in 1985. It is an enantioselective synthesis of a chiral alcohol by the condensation between a crotylboronate derived from diisopropyl-(/ ,/ )-tartrate and an achiral aldehyde. Therefore, it is known as the Roush crotylboration, ... 

Roush WR. Ando K, Powers DB, Palkowitz AD, Halterman RL. Asymmetric synthesis using diisopropyl tartrate modi-Hed (E)- and (Z)-crotylboronates preparation of the chiral crotylboronates and reactions with achiral aldehydes. J. Am. Chem.Soc. 1990 112 6339-6348. 

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