US 7,456,302 B2
Method for producing pentacyclic taxans
Akihiro Imura, Edogawa-Ku (Japan); Tatsuya Yamaguchi, Edogawa-Ku (Japan); Yoshihiro Takayanagi, Edogawa-Ku (Japan); and Seishiro Uchida, Edogawa-Ku (Japan)
Assigned to Daiichi Pharmaceutical Co., Ltd., Tokyo (Japan)
Appl. No. 11/579,140
PCT Filed Apr. 27, 2005, PCT No. PCT/JP2005/008034
§ 371(c)(1), (2), (4) Date Oct. 30, 2006,
PCT Pub. No. WO2005/105807, PCT Pub. Date Nov. 10, 2005.
Claims priority of application No. P 2004-136359 (JP), filed on Apr. 30, 2004.
Prior Publication US 2007/0167630 A1, Jul. 19, 2007
Int. Cl. C07D 305/14 (2006.01)
U.S. Cl. 549—471  [549/510; 549/60; 546/281.7] 5 Claims
 
1. A method for producing a compound of the following general formula (2) or its salt, which comprises reacting a compound of the following formula (1) with an alkali metal permanganate:

OG Complex Work Unit Drawing
(in formula (1), the dotted line part between the 6-position and the 7-position of the partial structure of the following formula (1-a):

OG Complex Work Unit Drawing
means that the bond of this part may be a double bond; boc means a tert-butoxycarbonyl group; Ac means an acetyl group; Bz means a benzoyl group; R1 means an alkyl group, a cycloalkyl group, a phenyl group or a monocyclic heterocyclic group, and the alkyl group, the cycloalkyl group, the phenyl group or the monocyclic heterocyclic group may be have one or more substituents selected from a group consisting of a halogen atom, an alkyl group, an alkoxy group, a phenyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, an acylamino group and an acyloxy group; R2 means a hydroxyl group optionally having a protective group);

OG Complex Work Unit Drawing
(in formula (2), R1, R2, boc, Ac and Bz have the same meanings as above).