反应详情

To a solution/suspension of the compound obtained in Step B (66.8 mmol) in THF (850 ml) at −65° C. there is added, dropwise, 1M DIBAL-H solution (546 mmol) over one hour and under an inert atmosphere. The reaction mixture is brought to −30° C. over 1 hour 30 minutes. 22 ml of water are added dropwise and then 22 ml of 15% aqueous sodium hydroxide solution at 0° C. and then 55 ml of water. MgSO4 (300 g) is added to the reaction mixture and stirring is carried out for 30 minutes. The suspension is filtered over Celite and washed with THF. The filtrate is evaporated to dryness to yield a pasty solid that is brown in colour. The residue is triturated in methanol, and the powder obtained is filtered off and dried in vacuo to yield the title product, which is used directly in the next Step.

1. additionthere is added
2. customat 0° C.
3. waitis carried out for 30 minutes
4. filtrationThe suspension is filtered over Celite
5. washwashed with THF
6. customThe filtrate is evaporated to dryness
7. customto yield a pasty solid
8. customThe residue is triturated in methanol
9. customthe powder obtained
10. filtrationis filtered off
11. customdried in vacuo