6-[tert-butoxycarbonyl-(3-hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-ylmethyl)-amino]-hexanoic acid 、
氯化苄 以gave 6-[(3-benzyloxy-5-hydroxymethyl-2-methyl-pyridin-4-ylmethyl)-tert-butoxycarbonyl-amino]-hexanoic acid benzyl ester (42) (3.2 g, 73% yield)的产率得到6-[(3-benzyloxy-5-hydroxymethyl-2-methyl-pyridin-4-ylmethyl)-tert-butoxycarbonyl-amino]-hexanoic acid benzyl ester