985. The occurrence of 1,2- or 1,4-addition in the reduction of some αβ-unsaturated ketones with metal hydrides

Reaction modes and polymerization of crotonic esters with lithium aluminum hydride

“…The amount of crotonaldehyde (11) is very small in all cases. This is because, as described by BROWN et aZ.10), (11') should be very unstable and undergo further reduction rapidly.…”

“…Results and Discussion 1. Reaction modes of LiAlH, with crotonic esters Reaction products obtained are as follows : butyric esters (double bond reduction products or conjugate addition products) (I), crotonaldehyde and crotyl alcohol (carbonyl reduction or carbonyl addition products) (11) and (III), n-butyl alcohol (carbonyl and double bond reduction product) (IV) and respective alcohols (V) which came from ester alkoxy groups. A probable reaction scheme is shown below.…”

Sur la réduction par NaBH4 de quelques nitriles α, β-insaturés

“…La plupart des Ctudes rapportCes dans la littCrature (9, 10, 13 -16, 22-25) (18,20,21). Dans la premiere Ctape de la rCaction, il y aurait une addition 1 :4 de l'anion borohydrure pour conduire a un complexe interrnidiaire qui s'hydrolyserait par l'action de l'isopropanol ou de l'eau (20,40) pour conduire au nitrile saturC.…”

“…L'Ctude du micanisme de ces reactions a aussi fait l'objet de nornbreux travaux (17)(18)(19)(20)(21). Cependant, aucun mecanisme n'a kt6 propose pour la reduction de nitriles insaturts quoique plusieurs Ctudes sur ce sujet aient Ct C publiies (22)(23)(24)(25).…”

Synthesis of deterium labeled plant ethylene precursor

“…It has been reported that reduction of n , p -unsaturated ketones with NaBH4 gives only the products of 1 ,Caddition rather than 1,2-addition in the presence of excess pyridine (9). Reduction of 5 was carried out in pyridine with NaE3H4.…”