Abstract
Condensation of 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-${\beta}$-D-glucopyranosyl bromide (2) with 1,2;3,4-di-O-isopropylidene-${\alpha}$-D-galactopyranose (3) in the presence of silver triflate and syn-collidine gave 1,2;3,4-di-O-isopropylidene-6-O-(3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-${\beta}$-D-glucopyranosyl)-${\alpha}$-D-galactopyranose (4) in $86{\%}$ yield. Cleavage of phthalimido group and de-O-acetylation with hydrazine, acetylation, and hydrolysis of isopropylidene and O-acetyl groups furnished 6-O-(2-acetamido-2-deoxy-${\beta}$-D-glucopyranosyl)-D-galactopyranose (1) with overall yield of $65.8{\%}$ starting from 3. Some other derivatives of 1 which have free hydroxyl groups at the specific position have also been prepared from 4. These compounds could be used as precursors for further glycosidation reactions.
Silver triflate와 syn-collidine 존재하에서 3,4,6-tri-O-acetyl-2-phthalimido-${\beta}$-D-glucopyranosyl bromide (2)와 1,2;3,4-di-O-isopropylidene-${\alpha}$-D-galactopyranose (3)를 반응시켜 1,2;3,4-di-O-isopropylidene-6-O-(3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-${\beta}$-D-glucopyranosyl)-${\alpha}$-D-galactopyranose (4)를 $86{\%}$의 수득률로 얻었다. 화합물 4를 hydrazine과 작용시켜 phthalimido기와 acetyl기를 동시에 제거한후, 다시 acetyl화하고 isopropylidene기와 O-acetyl기를 가수분해하면 6-O-(2-acetamido-2-deoxy-${\beta}$-D-glucopyranosyl)-D-galactopyranose (1)가 총수득율 $65.8{\%}$로 얻어졌다. 또한 화합물 4를 변형시켜 특정위치에 hydroxyl기를 가진 몇 가지 유도체도 합성하였다.
