Modular Construction of Protected 1,2/1,3-Diols, -Amino Alcohols, and -Diamines via Catalytic Asymmetric Dehydrative Allylation: An Application to Synthesis of Sphingosine

A new enantioselective catalysis has been developed for the one-step construction of methylene-bridged chiral modules of 1,2- and 1,3-OH and/or NH function(s) from delta- or lambda-OH/NHBoc-substituted allylic alcohols and "H2C=O"/"H2C=NBoc". A protonic nucleophile, either in situ-generated CH2OH or CH(2)NHBoc, is intramolecularly allylated to furnish eight possible 1,2- or 1,3-O,O, -O,N,-N,O, and -N,N chiral modules equipped with an ethenyl group in high yields and enantioselectivities. The utility of this method has been demonstrated in the five-step synthesis of sphingosine.