Synthesis, resolution, and absolute configuration of 1-phenyl-1-methyl-1-silacyclohexanone-2

Abstract

The synthesis and resolution of 1-phenyl-1-methyl-1-silacyclohexanone-2 by oxidative hydroboration of the related silacyclohexene to the silacyclohexanol, resolution of this via the strychnine salt of the phthalate half-ester, and subsequent oxidation of the silacyclohexanol to the silacyclohexanone is described. The carbon analog 1-phenyl-1-methylcyclohexanone-2 was also synthesized in optically active form. The (+)-enantiomers of the two ketones had similar optical rotatory dispersion curves, presenting convincing evidence for the identity of their configurations, and the carbon compound could be degraded without affecting the asymmetric center to (−)-(R)-2-phenyl-2-methylhexandioic acid, thereby establishing the absolute configurations of both compounds.