Tandem oxime formation—epoxide ring opening sequences for the preparation of oxazines related to the trichodermamides

A mild and straightforward method for the preparation of 4H-5,6-dihydro-1,2-oxazines from keto-epoxides via cyclisation of the intermediate oximes is reported, as is a preparative route to 3-amino-7,8-dimethoxychromen-2-one; these procedures were then employed to prepare a novel analogue of trichodermamide natural products.