American Chemical Society
ol0611090_si_003.cif (32.26 kB)

Cis and Trans Selective 1,4-Addition of a Lithium Dithioester Enolate to 4-O-TBS-2-cyclohexenone

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posted on 2006-08-31, 00:00 authored by Alan C. Spivey, Laetitia J. Martin, Damian M. Grainger, Jörg Ortner, Andrew J. P. White
The 1,4-addition of the lithium enolate of methyldithioacetate (LMDTA) to (±)-4-O-TBS-2-cyclohexenone (3) can be varied from being highly 3,4-trans selective to being highly 3,4-cis selective simply by varying the reaction temperature. This stereodivergency allows expedient syntheses of the corresponding trans and cis methyl esters 6t and 6c and derived bicyclic ketolactones 7t and 7c.