76347-09-6

Crotyldimethoxyborane is used as stereoselective aldehyde crotylborating agents; precursors of other crotylboronic esters via hydrolysis and esterification with diols.

Crotyldimethoxyborane is prepared in situ by metalation of (Z)-2-butene with n-Butyllithium-Potassium t-Butoxide followed by treatment of the resulting(Z)-crotylpotassiums with Fluorodimethoxyborane Diethyl Etherate diethyl etherate ((MeO)2BF.Et2O.

Crotyldimethoxyborane is stored in a refrigerator either neat or as a solution in an inert solvent such as CH2Cl2 or toluene. Allylboronic esters are moisture sensitive and are readily hydrolyzed by water to the allylboronic acids (which readily undergo aerial oxidation). The most stable allylboronic esters are the pinacol esters.