Study of cis/trans and endo/exo Diastereoselectivity in the [4+3]-Cycloaddition Reaction of 2-Functionalized Furans and Dimethyloxyallyl Cation : Preparation of Versatile Cycloheptane Synthons
A study on the influence of steric and electronic effects of a function attached at C-2 of furans in the yield and diastereoselectivity of [4+3] cycloaddition reactions with oxyallyl cations is presented. In almost all studied furans a <I>cis</I> diastereospecificity and a high <I>endo</I> diastereoselectivity is observed. Increasing bulkyness of the function attached at C-2 of furans, increases the <I>endo</I> diastereoselectivity, but decreases yield. Increasing the electronic density of the furan system, by an electron donating group attached at C-2, increases yield and diastereoselectivity.
- Chemistry letters
Chemistry letters 1997(9), 847-848, 1997-09
The Chemical Society of Japan