1998 cycloaddition reactions

cycloaddition reactionsO 0070

10 - 049Diels–Alder Reactions of 5-Alkyl-1,3-cyclopentadienes. — The titlereaction, studied with dienes (I), (VII), and (IX), and a number of dienophiles,proceeds mainly with anti selectivity. This result is in accordance with acomputational model of control by steric hindrance. The methoxymethylsubstituted diene (Ic) shows an unexpectedly high preference for syn additionwith dienophiles (II) and (XII), probably a result of conformational differencein the transition state relative to the transition states for addition syn to simplealkyl groups. — (LETOURNEAU, J. E.; WELLMAN, M. A.; BURNELL, D.J.; J. Org. Chem. 62 (1997) 21, 7272-7277; Dep. Chem., Memorial Univ., St.John’s, Newfoundland A1B 3X7, Can.; EN)

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1998 cycloaddition reactions

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