Synthesis of chiral intermediates of quinine alkaloids and (+)-dihydroantirhine

Abstract

(4R,5R)-2-Ethoxy-5-ethyl-4-methoxycarbonylmeth yl-3,4,5,6-tetrahydro-2H-pyran 3, which has been enantioselectively prepared, is converted into the cis-substituted lactone 11 by treatment with propanedithiol in the presence of boron trifluoride–diethyl ether. The product 11 is converted into the synthetic intermediate 7 of quinine alkaloids and the synthetic precursor 19 of (+)-dihydroantirhine 10.

References

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