Synthesis and crystal structure of 7,9-dideacetyl-1-deoxybaccatinVI

7,9-dideacetyl-1-deoxybaccatinVI was synthesized from 1-deoxybaccatinVI and its crystal structure was determined by X-ray crystallographic techniques. The compound (C₃₃H₄₂O₁₁·2CH₄O) crystallizes into monoclinic space group P2₁ with unit cell parameters: a=8.654(17) ?, b=16.470(5) ?, c=12.671(3) ?, β=97.63(2)°, and Z=2. The X-ray results demonstrated that the reaction of 7,9,10-Trideacetyl-1-deoxy-baccatinVI with Ac₂O in tetrahydrofuran, using CeCl₃ as catalyst, yielded monoacetylated product 7,9-dideacetyl-1-deoxy baccatinVI. In the structure, the six-membered A ring exhibits boat conformation, the eight-membered B ring adopts boat-chair conformation, and the six-membered C ring exhibits sofa conformation.