777918-06-6Relevant academic research and scientific papers
Fate of diradicals in the caldera: Stereochemistry of thermal stereomutation and ring enlargement in cis- and trans-1-cyano-2(E)- propenylcyclopropanes
Doering, William Von E.,Barsa, Edward Albert
, p. 12353 - 12362 (2007/10/03)
This study of thermally induced stereomutation and ring enlargement in both (-)-trans-1-cyano-2(E)-propenylcyclopropane [(-)-trans-1] and (+)-cis-1-cyano-2(E)-propenylcyclopropane [(+)-cis-1] to cyclopentenes definitively contraindicates the usefulness of Woodward-Hoffmann rules of orbital symmetry as a theoretical basis for predicting the stereochemistry of the products. From both diastereomers, the same (+)-trans-4-cyano-3- methylcyclopentene [(+)-trans-2] is the major product among the four diastereomeric products, "allowed" and formally the result of a single internal rotation of the cyano-bearing carbon atom from (-)-trans-1, "forbidden" and the result of zero internal rotations from (+)-cis-1. Stereomutation and ring enlargement are discussed in detail in terms of rotational propensity, thermodynamic preference, and the possible role of diradicals in transit and diradicals as intermediates in a caldera.
Total synthesis of racemic and optically active sarkomycin
Miko?ajczyk, Marian,Zurawiński, Remigiusz,Kie?basin?ski, Piotr,Wieczorek, Micha? W.,B?aszczyk, Jaros?aw,Majzner, Wies?aw R.
, p. 356 - 365 (2007/10/03)
trans-3-Carboxy-2-diethoxyphosphorylcyclopentanone (11), a key precursor of sarkomycin 1, has been synthesized in the rhodium(II) acetate promoted cyclization of diethyl 1-diazo-2-oxohept-6-enephosphonate (9), followed by transformation of the 3-vinyl moi
