Formation and efficient addition of cerium(III) derivative of acetonitrile to ketones
摘要:
The cerium(III) derivative of acetonitrile undergoes addition with ketones efficiently. It adds effectively to hindered ketones and gives 1,2-adduct exclusively with conjugated enones.
Electroreduction of gamma and delta-cyano ketones in i-PrOH with Sn cathode gave alpha-hydroxy ketones and their dehydroxylated ketones as the intramolecularly coupled products. Guaiazulene, (-)-valeranone, polyquinanes, dihydrojasmone, methyl dihydrojasmonate, and rosaprostol have been synthesized by utilizing this electroreductive intramolecular coupling of gamma and delta-cyano ketones in one of the key steps. Similarly, electroreduction of a mixture of ketone and nitrile gave the corresponding intermolecularly coupled product. The product obtained by the electroreductive intermolecular coupling of (+)-dihydrocarvone with acetonitrile has been found to be the precursor of an effective chiral ligand for the enantioselective addition of diethylzinc to aldehydes.
Dobrev, Alexandre; Ivanov, Christo; Lattes, Armand, Bulletin de la Societe Chimique de France, 1987, # 6, p. 1084 - 1088
The SmI2-mediated coupling of alpha-bromoacetonitrile and alpha-bromopropionitrile with aliphatic ketones and aldehydes produces beta-hydroxynitriles in good yields. Reactions typically proceed with little diastereoselectivity, but selectivity enhancement occurs with the addition of tetra-n-hexylammonium bromide. (C) 2000 Elsevier Science Ltd. All rights reserved.