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

Participants

Reaction Steps

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.

Provenance & Evidence