Synthesis of β-1-homonojirimycin and β-1-homomannojirimycin using the enzyme aldolase

Abstract

The four stereoisomers of the four-carbon azido sugar 11 have been stereoselectively synthesised by a route involving Sharpless epoxidation and all are found to be substrates for rabbit muscle fructose 1,6-bisphosphate aldolase, giving (after treatment with phosphatase) 6-azido-6-deoxyheptuloses 14; hydrogenation of 14a and 14b gave β-1-homomannojirimycin 15a and β-1-homonojirimycin 15b with high selectivity.