[GRAPHICS]The diastereomers of 6-amino-cyclohex-3-ene- 1,2-diols 1 (4-deoxy-3-conduramines), key building blocks for the syntheses of a large range of natural products, have been enantioselectively prepared. Diastereoselective dihydroxylation of the compounds provided a new family of aminocyclitols 2 (deoxyinosamines). The key reactions of our syntheses are Sharpless catalytic asymmetric epoxidation, diastereoselective addition of vinylmetal reagents to the aldehydes, and ring-closing metathesis (RCM).
New Stereodivergent Approach to 3-Amino-2,3,6-trideoxysugars. Enantioselective Synthesis of Daunosamine, Ristosamine, Acosamine, and Epi-daunosamine
作者:Xavier Ginesta、Mireia Pastó、Miquel A. Pericàs、Antoni Riera
DOI:10.1021/ol034843h
日期:2003.8.1
[reaction: see text] An enantioselective preparation of the four diastereomeric 3-amino-2,3,6-trideoxy-hexoses, key components of anthracycline antibiotics, has been developed. Sharpless catalytic asymmetric epoxidation of the (2E)-2,5-hexadien-1-ol, regioselectivering opening with azide, followed by convenient functional group transformations, afforded the key aldehydes cis- or trans-6 in any configuration