A SYNTHETIC STUDY TOWARDS SK,6S-ASTERISK)-6-(2-INDENYL)SPIRO[4,5]DECAN-2-ONE

The title compound is an immediate precursor to the model compounds de signed for probing the elusive hydroxy-carbanion interaction. The rela tive configuration of the spirocycle is controlled by a contrasteric a lkylation of methyl 2-alkoxy-methylcpclohexanecarboxylate. The constru ction of the indene moiety is arranged later in the synthesis for the convenience of incorporating the C-13 atoms, which are needed in the e ventual spectroscopic studies. Simple 1,2-elimination (commonly used f or preparing 1- or 3-substituted indenes) is found unsuitable here for the formation of the double bond in the indene ring, as the by-produc ts caused by the migration of the substituent at C-2' are very difficu lt to remove.