Synthesis of homochiral spiro [4.4]nonane-l,6-diols

Homochiral cis, cis-; cis,trans and trans,trans-spiro4,4]-nonane-1,6-diols were prepared via diastereoselective reduction of enantiomerically pure spiro4.4]nonane-l,6-dione (1) with the corresponding reducing agents: lithium n-butyldiisobutylaluminium hydride for cis,cis-diol (2) with 88% yield; BH₃·THF for cis, trans-diol (8) with 91% yield; LiAlH₄ for trans,trans-diol (4) with 15% yield.