19340-09-1Relevant academic research and scientific papers
Conformational and Heteroatom Influences During Sodium Borohydride Reduction of Some Substituted 1-Hetera-4-cyclohexanones
Nanjappan, P.,Dhandapani, C.,Natarajan, K.,Ramalingam, K.
, p. 623 - 630 (2007/10/02)
The rates of sodium borohydride reduction of a number of variously substituted 1-hetera-4-cyclohexanones have been measured in isopropyl alcohol at 10 deg C.The trends in reactivity are very similar to those observed in the equilibrium constants for the formation of cyanohydrins of 1-hetera-4-cyclohexanones.The decreased ease of reduction, reflected in the rate retardation in these ketones , is rationalised based on the substituent and conformational effects of the ring and transannular dipolar "through-space-effects" is suggested to explain the rate differences among them.The effect of heteroatom on the reduction rates follows same orders as the electronegativities of the heteroatoms, namely O > N > S > Se.The rate differences could be traced to a combination of the varied polar effects of the heteroatoms and their varied covalent radii resulting in different conformational transmission effects in shaping the ring.
