Maciej Mikina

New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins*

This account outlines the results obtained in the authors laboratory on the application of phosphonate reagents in the synthesis of biologically active cyclopentanones and cyclopentenones. The synthesis and reactivity of 3-phosphorylmethyl-cycloalkenones is discussed as a platform for developing the first synthesis of enantiomeric isoterreins as well as the synthesis of racemic and optically active prostaglandins B 1a. A different strategy for the total synthesis of racemic and enantiomeric forms of sarkomycin and rosaprostol is described which involves in a key step intramolecular carbenoid cyclization of the corresponding a-diazo-b-ketophosphonates.

Synthesis and conformation of 2-dimethoxyphosphoryl-1,3-diselenanes. The first evidence for SeCP anomeric interactions.

Abstract Analysis of the 1 H and 13 C NMR spectra of conformationally labile 2-dimethoxyphosphoryl-5,5-dimethyl-1,3-diselenane and equilibration of the diastereoisomeric cis - 2 and trans - 2 revealed that the anomeric effect of magnitude about ΔG° A E =10 kJmol −1 is operating in SeC- system. Crystallographic data are in accord with the interplay of the n S e -σ* C − P negative hyperconjugation and repulsive interactions between lone electron pairs on phosphoryl oxygen and lone pairs on the endocyclic selenium atoms in trans - 2 .

Horner Olefination Reaction in Organic Sulfur Chemistry and Synthesis of Natural and Bioactive Products

This article outlines the results of our work on the application of the Horner olefination reaction for the synthesis of unsaturated sulfur compounds. A general synthesis of racemic and optically-active α,β-unsaturated sulfoxides by the Horner reaction with α-sulfinylmethylphosphonates as olefination reagents is presented. We demonstrated how the structure of the phosphonate moiety may control the E- and Z-stereoselectivity in the above reaction. The use of racemic and optically-active α-sulfinylvinylphosphonates in tandem Michael addition/Horner olefination reaction leads to a wide range of carbocyclic and heterocyclic vinyl sulfoxides. In second part of this account a new strategy for the synthesis of functionalized cyclopentenones is briefly described. The synthesis and reactivity of 3-phosphorylmethyl-cyclopentenones is discussed as a platform for developing the synthesis of racemic rosaprostol, enantiomeric prostaglandin B1 methyl esters, enantiopure isoterreins, natural and unnatural neplanocin A and enantiomeric forms of phytoprostane B 1 type I.

A general approach to the synthesis of functionalized cycloalkenones. Total synthesis of iso-terrein

Abstract The synthesis and chemical behaviour of bis-β-ketophosphonates are described. A new approach to the synthesis of chiral iso-terrein has been developed which utilizes the bis-β-ketophosphonate chemistry.

The First Observation of γ-Sila-Pummerer Rearrangement

Abstract 2-Sulfinyl-3-trimethylsilylmethylcycloalkanones unexpectedly undergo γ-sila-Pummerer rearrangement. The first examples of this new type of rearrangement are presented. GRAPHICAL ABSTRACT