An improved synthesis of cyclopropanes from stabilized phosphonates and 1,2-dioxines.
Addition of stabilized Horner-Wadsworth-Emmons (HWE) phosphonates to substituted 1,2-dioxines leads to diastereomerically pure di- and trisubstituted cyclopropanes in high yields and represents a viable alternative to ylides in the cyclopropanation reaction involving 1,2-dioxines. While yields are comparable, reaction times with these stabilized phosphonates were accelerated and the diastereoselectivity for this cyclopropanation reaction was significantly greater than for the previously reported examples employing ylides.
Kimber
Marc C
MC
Department of Chemistry, Adelaide University, S.A., Australia, 5005.
Taylor
Dennis K
DK