140. “Diastereoselective and enantioselective reduction of tetralin- 1,4-dione”
     E.P. Kündig, A. Enriquez-Garcia,
     Beilstein J. Org. Chem. 2008, 4, No. 37.

Background

The chemistry of tetralin-1,4-dione, the stable tautomer of 1,4-dihydroxynaphthalene, has not been explored previously. It is readily accessible and offers interesting opportunities for synthesis.

Results

The title reactions were explored. L-Selectride reduced the diketone to give preferentially the cis-diol (d.r. 84 : 16). Red-Al gave preferentially the trans-diol (d.r. 13 : 87). NaBH₄, LiAlH₄, and BH₃ gave lower diastereoselectivities (yields: 76–98%). Fractional crystallization allowed isolation of the cis-diol and the trans-diol (55% and 66% yield, respectively). Borane was used to cleanly give the mono-reduction product. Highly enantioselective CBS reductions afforded the trans-diol (72% yield, 99% ee) and the mono-reduction product (81%, 95% ee).

Conclusion

Diastereoselective and enantioselective reductions of the unexplored tetralin-1,4-dione provides a very convenient entry into a number of synthetically highly attractive 1,4-tetralindiols and 4-hydroxy-1-tetralone.

DOI : 10.3762/bjoc.4.37 

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