Four allylic dioxolanes were prepared and reacted with several dienes in the presence of Lewis acids, affording [4+3] cycloadducts. The reaction could be conducted with catalytic amounts of Lewis acid. The use of a chiral Lewis acid gave a cycloadduct with only a low enantiomeric excess. (c) 2006 Elsevier Ltd. All rights reserved.
Four allylic dioxolanes were prepared and reacted with several dienes in the presence of Lewis acids, affording [4+3] cycloadducts. The reaction could be conducted with catalytic amounts of Lewis acid. The use of a chiral Lewis acid gave a cycloadduct with only a low enantiomeric excess. (c) 2006 Elsevier Ltd. All rights reserved.