Methods for the synthesis of polyhydroxylated piperidines by diastereoselective dihydroxylation: Exploitation in the two-directional synthesis of aza-C-linked disaccharide derivatives

• Andrew Kennedy,
• Adam Nelson and
• Alexis Perry

Beilstein J. Org. Chem. 2005, 1, No. 2, doi:10.1186/1860-5397-1-2

• configurations may be easily prepared. Our synthetic strategy is outlined in Scheme 1. We have previously shown that the configuration of 1,3-amino alcohol derivatives, such as 10, may be controlled by the addition of a lithium enolate to an N-sulfinyl imine (→ 9, for example) and diastereoselective reduction

• (Scheme 2).[24][25][26][27][28][29][30][31][32] Two-directional[33] oxidative ring expansion of 1,3-difuryl 1,3-amino alcohol derivatives 4 would yield a densely functionalised bis-enone which would be ripe for further functionalisation. The term "two-directional synthesis" is usually used to describe the

• materials were prepared from the 1,3-amino alcohol derivatives 1,3syn- and 1,3anti-10 (Scheme 6). Treatment of the difuryl 1,3-sulfinimido alcohols 1,3syn- and 1,3anti-10 with NBS in buffered THF-water precipitiated sulfonamide oxidation and two-directional ring expansion of both furan rings;[50] the crude