E. Torregiani et al., THE CHEMISTRY AND OCCURRENCE OF TAXANE DERIVATIVES .23. A SERENDIPITOUS CLUE TO THE BIOGENESIS OR TAXCHINS, Tetrahedron letters, 36(39), 1995, pp. 7127-7128
Acetylation of 3a was accompanied by the formal anti-Markovnikov addit
ion of acetic acid to the 4(20)-double bond, giving a compound (2b) wi
th the ring C functionalization of taxchins.