A general approach to 3-phosphorylmethyl cycloalkenones by intramolecular Horner-Wittig reaction of bis-.beta.-ketophosphonates
作者:Marian Mikolajczk、Maciej Mikina
DOI:10.1021/jo00101a041
日期:1994.11
The reaction of dicarboxylic acid diesters with lithiomethylphosphonates was found to give bis-beta-keto phosphonates 1 [(RO)(2)P(O)CH2C(O)](2)(CH2)(n) (n = 2, 3, 4), a new class of compounds. Their cyclization under basic conditions provides an easy access to five-, six- and seven-membered 3-phosphorylmethyl cycloalkenones 2. The cyclization of 1,6-bis(dialkoxyphosphoryl)hexan-2,5-dione (1a,d) was found to be bidirectional in course and a competition between the intramolecular Horner-Wittig and Knoevenagel reaction was observed. It was demonstrated that the latter reaction is reversible which allows conversion of the Knoevenagel reaction product into the Horner-Wittig reaction product (for example 5b into 2d). Two efficient methods for the synthesis of 2- and 3-functionalized cycloalkenones 6 and 7 involving alkylation and olefination of the cycloalkenones 2 anion were devised.
Mikolajczyk Marian, Mikina Maciej, J. Org. Chem., 59 (1994) N 22, S 6760-6765
作者:Mikolajczyk Marian, Mikina Maciej
DOI:——
日期:——
Straightforward synthesis of functionalized (E)-3-acylacrylic acids
An experimentally simple, mild and straightforward synthetic route towards diversely functionalized (E)-3-acylacrylic acids is described, with Horner–Wadsworth–Emmons (HWE) reaction as the key step. The substrate scope and limitations of the HWE reaction were investigated with a range of β-ketophosphonates. Glyoxylic acid monohydrate was demonstrated to be fully compatible with the HWE reaction conditions