109307-70-2Relevant academic research and scientific papers
New Approaches to the Synthesis of Vitamin D Metabolites. 2. The Effect of Some Substituents on Stereochemistry in the Intramolecular Cycloadditions of Nonatrienes
Parker, Kathlyn A.,Iqbal, Tahir
, p. 4369 - 4377 (2007/10/02)
Intramolecular Diels-Alder reactions of 8-methyl-1,3,8-nonatrienes 5 and 6 were studied to determine the effects of substituents on the stereochemistry of ring closure.Substituents at C-3 favor closure to trans-hydrindenes; likewise, a C-7 alkyl group favors closure to trans-hydrindene products.Substrates bearing a C-7 alkyl substituent afforded products in which the alkyl substituent was invariably cis to the angular methyl group (34 and 35).The ratio of trans:cis fused hydrindenes was shown to be solvent-dependent; yields were improved when closures were effected in dimethylaniline.
