Reaction of cyclic γ-cyanoketones with 3 equiv. of SmI2 in the presence of t-BuOH as a proton source in HMPA–THF without photoirradiation gave the desired α-hydroxycycloalkanones along with overreduced ketones after hydrolysis. In the absence of t-BuOH, the formation of the overreduced ketones was depressed and the yields of the α-hydroxyketones increased, while the reaction proceeded slowly.
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.
Synthesis of ketones by cyclization of cyano and acetylenic radicals: use of .delta.-hydroxy nitriles and .delta.- or .epsilon.-hydroxy acetylenes
作者:Derrick L. J. Clive、Pierre L. Beaulieu
DOI:10.1021/jo00181a046
日期:1984.4
Watanabe, Pharmaceutical Bulletin, 1957, vol. 5, p. 426,429
作者:Watanabe
DOI:——
日期:——
A Facile Conversion of Substituted Cyclobutanones to Cyclopentanones by CH2I2/SmI2 System