438620-29-2Relevant articles and documents
Addition of chiral enolates to N-alkyl-3-acylpyridinium salts. Total synthesis of (+)-16-epivinoxine and (-)-vinoxine
Bennasar, M.-Llusa,Zulaica, Ester,Alonso, Yolanda,Vidal, Bernat,Vazquez, Jesus T.,Bosch, Joan
, p. 95 - 106 (2007/10/03)
Chiral enolates of indolylacetyl derivatives 6a-f undergo addition to pyridinium salt 7 with complete trans-selectivity and varied diastereofacial selectivities to give, after acid-induced cyclization of the intermediate 1,4-dihydropyridines, the vinoxine-related tetracycles 8a-f. Starting from (S)-prolinol indolylacetamide 6e, subsequent elaboration of the ethylidene substituent from tetracycle 8e and removal of the chiral auxiliary has resulted in a straightforward synthesis of (+)-16-epivinoxine and (-)-vinoxine.