Convenient methods for regio- and/or chemo-selective O-deacylation of taxinine, a naturally occurring taxane diterpenoid

Selective O-deacylations of taxinine la, readily available from needles of Taxus cuspidata, at C-2, C-5 and C-9,10 have been accomplished by treatment with barium hydroxide octahydrate, sodium bis(2-methoxy-ethoxy)aluminium hydride (Red-Al(R)) or diisobutylaluminium hydride (DIBAL-H) under mild conditions to give 2,9,10-tri-O-deacetyltaxinine 4b, 2-O-deacetyltaxinine 4c, 5-O-decinnamoyltaxinine (taxinine A, 5a) and 2,5-di-O-deacyltaxinine (taxuspine G, 5b), respectively, which are expected to be useful synthetic intermediates for biologically active taxinine derivatives.