Sialyl Lewis X (SLe(x)) analogs 2a and 2b were synthesised, where the N-acetyl-D-glucose and the D-galactose units of SLe(x) 1 were replaced with an alkyl and a heteroalkyl spacer. Sulphate ester 6i was also synthesised from alcohol 6b and chlorosulphonic acid. A novel promoter. silver mercaptoethanesulphonate. was used to synthesise alpha-sialosides 2c, 7b and 7c.