150730-16-8Relevant academic research and scientific papers
Directive effect of the 2- and 3-axial hydroxy groups that appeared in the complex metal hydride reduction of cyclohexanones
Senda,Kikuchi,Inui,Itoh
, p. 237 - 242 (2007/10/03)
A directive effect of the 2-axial hydroxy group appeared in the LiAlH4, NaBH4, and Zn(BH4)2 reduction of cyclohexanone, while the 3-axial hydroxy group exhibited a steric hindrance. The distance between the carbonyl carbon and the hydroxy group interacting with the hydride reagent was responsible for such a difference. In the reduction of Na[B(OAc)3H], the 2- and 3-axial hydroxycyclohexanones gave the products obtained by the hydride approaching from the side of the hydroxy group. The key point of the stereoselectivity was the formation of Na[B(OAc)2(OR)H, which was more reactive than the parent hydride, by exchanging the acetate ion with the alkoxide. Although the reduction was performed under the condition that the hydride/substrate ratio was 1, the conversion of the hydroxy ketone to an alcohol were 4, NaBH4, and Zn(BH4)2 reductions in tetrahydrofuran. The conversions in the NaBH4 reduction in ethanol were > 90%.
A Probe of Cieplak's Proposal: Effect of 2-Axial Substitution on Reactivity in the LiAlH4 Reduction of Cyclohexanones
Senda, Yasuhisa,Nakano, Sigeru,Kunii, Hiromi,Itoh, Hiroki
, p. 1009 - 1010 (2007/10/02)
The relative reactivities of cyclohexanones in which the 2-axial position is substituted by methyl or methoxy group in LiAlH4 reduction strongly support the Cieplak model which focuses on the importance of stabilisation of the transition state by antiperi
