81176-75-2Relevant academic research and scientific papers
A GENERAL METHOD FOR THE SELECTIVE REDUCTION OF KETONES IN THE PRESENCE OF ENONES.
Ward, Dale E.,Rhee, Chung K.,Zoghaib, Wajdi M.
, p. 517 - 520 (2007/10/02)
Ketones can be reduced in the presence of conjugated enones by sodium borohydride in 50percent methanol in dichloromethane at -78 deg C.The selectivity is generally excellent.In favorable cases the reaction can be carried out at room temperature in dichloromethane with acetic acid as catalyst.
SELECTIVITE DE LA REDUCTION D'α-ENONES POLYCYCLIQUES PAR LES BOROHYDRURES: EFFET DE L'ADDITION DE TETRAMETHYL-ETHYLENEDIAMINE AU BOROHYDRURE DE TETRABUTYLAMMONIUM
D'incan, E.,Loupy, A.,Maia, A.,Seyden-Penne, J.,Viout, P.
, p. 2923 - 2927 (2007/10/02)
Δ1,9octalone, Δ1,9-10-methyl octalone and testosterone were reduced by NBu4BH4, alone or in the presence of tetramethylethylenediamine (TMEDA), in THF and in toluene.With TMEDA, the first step of the reduction is the regioselective 1,4 attack by BH4(1-) which leads either to the saturated ketones or to the corresponding saturated alcohols.The results observed under different conditions were interpreted by the intervention of various reductive species: diborane, enoxyborohydrides in the absence of TMEDA, amine-borane in its presence.
SELECTIVITE DE LA REDUCTION DE L'ANDROSTEN-4 DIONE-3,17 ET DE LA PROGESTERONE PAR DIVERS BOROHYDRURES: ROLE DE L'ASSISTANCE ELECTROPHILE PAR LE CATION OU UN SOLVANT HYDROXYLE
D'Incan, E.,Loupy, A.,Restelli, A.,Seyden-Penne, J.,Viout, P.
, p. 1755 - 1760 (2007/10/02)
The reduction of Δ4-androsten-3,17 dione 1 and of progesterone 2 by nBu4NBH4 is highly chemisoselective: in THF only the α-enone moiety is reduced, the saturated C17 or C20 keto group being kept unchanged.When TMEDA is added, saturated alcohols are obtained, without any allylic alcohol when the reaction goes to completion.However this reduction is poorly stereoselective as 70:30 mixtures of A/B cis and trans ring junction compounds are obtained.In MeOH, the saturated keto group is more than 90percent selectively reduced.However, the reduction of 1 and 2 by LiBH4 and Zn(BH4)2 is poorly chemioselective.These results are interpreted in terms of competition between electrophilic assistance and steric effects.
