反应详情

A solution of 38 (3.3 g, 15 mmol) and p-toluenesulfonic acid monohydrate (0.17 g, 0.9 mmol) in aqueous MeOH (21 mL, MeOH: H2O 20:1) was stirred at rt for 16 h, then neutralised by the addition of saturated NaHCO3 aq. and the methanol was removed in vacuo. The residue was extracted with t-BuOMe (3×) and the organic phase was dried (Na2SO4) and evaporated to dryness to give 39 compound (2.4 g, 95%) which was used as such in the next step:

1. customthe methanol was removed in vacuo
2. extractionThe residue was extracted with t-BuOMe (3×)
3. dry with materialthe organic phase was dried (Na2SO4)
4. customevaporated to dryness