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Stereochemistry of the Reactions of Cyclic Ketones with Lithium Aluminum Hydride and Methyllithium. IV. The Stereochemistry of the Reactions in 2,2‐Dimethyl‐4‐ t ‐Butylcyclohexanone Systems
Author(s) -
Rei MinHon,
Chen C. L.,
Liu H. L.
Publication year - 1983
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.198300001
Subject(s) - chemistry , methyllithium , aluminum hydride , lithium (medication) , ketone , cyclohexanone , alcohol , hydride , medicinal chemistry , ion , organic chemistry , catalysis , hydrogen , medicine , endocrinology , methoxide
Previous publication showed that the stereochemistry of lithium aluminum hydride reduction of cyclic ketones can be evaluated by the use of an empirical equation, . This paper reports further test of this relationship in the new system of 2,2‐dimethyl‐4‐ t ‐butyl‐cyclohexanone. Lithium aluminum hydride reduction of this ketone yields 95.6% trans ‐alcohol (lit., 95.9%) corresponding to D̊( D̊G *) H of 1.67 Kcal / mol . With methyllithium, the ketone formed 77.5% of trans ‐alcohol (D̊( D̊G *) D̊fs = 0.67 Kcal / mol ). These data give a calculated D̊G * = 0.74 Kcal / mol which agrees well with the literature value of 0.87 or 0.28 Kcal / mol . Structural assignments of 2,2‐dimethyl‐4‐ t ‐butylyclohexanone, 1,2,2‐trimethyl‐ cis ‐ and trans ‐4‐ t ‐butylcyclohexanols by pmr spectroscopic method are also given.