反应详情

Saishin N (3.68 g, 20 mM) was treated with 2,4-dinitrobenzoic acid (6.79 g, 32 mM) according to the procedures described in Example 20, forming a mixture of 4-(2,4-dinitrobenzoyloxy)-5-hydroxy-2,6,6-trimethyl-2-cyclohepten-1-one and (per acyl transfer reaction) 5-(2,4-dinitrobenzoyloxy)-4-hydroxy-2,6,6-trimethyl-2-cyclohepten-1-one, and then the mixture was reduced at the nitro groups according to the procedures described in Example 19 and fractionated by silica gel column chromatography using hexane-ethyl acetate (3:2) as an eluent. The first eluted portion was crystallized from a mixed solution of ethyl acetate and hexane to obtain 1.65 g (26%) of 4-(2,4-diaminobenzoyloxy)-5-hydroxy-2,6,6-trimethyl-2-cyclohepten-1-one (AU242) as a brown powder. Melting point: 154° to 156° C.

1. customforming
2. customThe first eluted portion was crystallized from a mixed solution of ethyl acetate and hexane