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1,4‐pentadien‐3‐ones, 31. 1‐(1‐cyclohexenyl)‐1‐propen‐2‐ones: Synthesis, properties, and stereoselective formation of 3‐aryl‐4‐(1‐cyclohexenylcarbonyl)perhydro‐1‐naphthalenones by sequential michael reaction
Author(s) -
Richter Friedrich,
Otto HansHartwig
Publication year - 1990
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199019900102
Subject(s) - chemistry , stereoselectivity , cyclohexanol , cyclohexene , butyllithium , lithium (medication) , aryl , cyclohexanone , bicyclic molecule , derivative (finance) , medicinal chemistry , stereochemistry , organic chemistry , catalysis , medicine , alkyl , endocrinology , financial economics , economics
On rearrangement, 1‐ethynyl‐1‐cyclohexanol ( 1 ) yields 1‐acetyl‐1‐cyclohexene ( 2 ). At −78°C in the presence of LDA, 2 reacts with aldehydes/ketones yielding the aldols 5 / 8 , which are dehydrated to the title compounds 6 or 9 . At room temp., a reaction between the lithium derivative of 2 and 6 ensues, yielding the bicyclic products 10 . These can also be prepared independently from isolated 6 and 2 with LDA or butyllithium in high yields. The stereochemistry is elucidated by spectroscopic methods, and the minimum energy conformation of 10a is calculated. The stereoselective formation of 10 is explained by a lithium‐controlled sequential Michael reaction.