debenzylated to 3-O-unsubstituted hexofuranose 11d. By reduction with sodium dihydrobis(2-methoxyethoxy)aluminate, followed by acid hydrolysis, these key intermediates 11a, 11b, and 11d provided the title L-fucoses 13 (together with a minor proportion of D-altropyranoses 14) having as phenylphosphinylidene group in place of the ring oxygen. Compounds 13 and 14 were converted into per-O-acetyl derivatives for
                                    1,2-O-Isopropylidene-3-O-methyl-6-O-tosyl-β-D-arabino-hexofuranos-5-ulose (9a) 及其 3-O-benzyl 同源物 (9b) 由 1, 2:5,6-二-O-异亚丙基-β-D-altrofuranose 分 4 个步骤。在 
DBU 存在下将苯基
次膦酸甲酯加入 9a 和 9b,然后用 Raney Ni 还原,得到 (5R 和 5S)-5,6-dideoxy-1,2-O-isopropylidene-5-[(甲氧基) 
苯基膦基] -3-O-甲基-β-D-阿拉伯-己基
呋喃糖(11a)和3-O-苄基同源物(11b),分别。后一化合物(11b)被去苄基化为3-O-未取代的己
呋喃糖11d。通过用二氢双(2-甲氧基乙氧基)
铝酸钠还原,然后进行酸
水解,这些关键中间体 11a、11b 和 11d 提供了标题 
L-岩藻糖 13(连同小比例的