Ethyl 2-[(2,2-Dimethyl-1,3-dioxolan-4-yl)methyl]-2H-thieno[3,2-e]-1,2-thiazine-3-carboxylate 1,1-dioxide → 7-Hydroxymethyl-7,8-dihydro-5H-[1,4]oxazino[4,3-b]thieno[3,2-e]-1,2-thiazine-5-one 10,10-dioxide
Reaction equation
CC1(C)O[CH:5]([CH2:7][N:8]2[C:13]([C:14]([O:16]CC)=[O:15])=[CH:12][C:11]3[CH:19]=[CH:20][S:21][C:10]=3[S:9]2(=[O:23])=[O:22])[CH2:4][O:3]1.O.FC(F)(F)C(O)=O>>[OH:3][CH2:4][CH:5]1[O:16][C:14](=[O:15])[C:13]2[N:8]([S:9](=[O:22])(=[O:23])[C:10]3[S:21][CH:20]=[CH:19][C:11]=3[CH:12]=2)[CH2:7]1Participants
3
Procedure
A solution of the product from Step B (18 g, 21.4 mmol) in a water/trifluoroacetic acid mixture (1:9) was stirred for 12 h. The solid which formed was collected by filtration, washed with hexane, and dried to give 11.9 g (86%) of a colorless solid: mp 210°-212° C.