Journal of the Chemical Society. Perkin transactions I p. 1191 - 1196 (1981)
Update date:2022-09-26
Topics: Retrosynthetic analysis Final steps Construction of the Core Structure Assembly of Fragments
Kometani, Tadashi
Yoshii, Eiichi
The syntheses of 9-demethoxyeleutherins and 9-deoxynanaomycin A methyl ester starting from indan-1-one derivatives are described.Lemieux-Johnson oxidation of the indene (15) derived from 4,7-dimethoxy-2-methylindan-1-one (14) afforded the diketone (16).The diol (17) obtained by lithium aluminium hydride reduction of (16) was treated with hydrochloric acid to give a ca. 1:2 mixture of cis-5,8-dimethoxy-1,3-dimethylisochroman (18) and the trans-isomer (19).Treatment of (16) with hydrogen bromide in acetic acid followed by catalytic reduction gave exclusively the cis-isochroman (18).Oxidative demethylation of the isochromans (18) and (19) afforded the quinones (22) and (23), benzannelation of which in two steps yielded 9-demethoxyeleutherin (24) and 9-demethoxyisoeleutherin (25) respectively.The same oxidation of the indene (32) derived from 4,7-dimethoxyindan-1-one (28) afforded the keto-aldehyde (33), which was treated with methoxycarbonylmethylenetriphenylphosphorane to give the conjugated ester (34).Reductive cyclisation of (34) with sodium borohydride afforded a ca. 1:3.5 mixture of cis-5,8-dimethoxy-3-methoxycarbonylmethyl-1-methylisochroman (35) and the trans-isomer (36).Oxidative demethylation of (36) followed by benzannelation produced 9-deoxynanaomycin A methyl ester (39).
View MoreContact:86-21-50966856
Address:Building 5,300 Chuanzhan Road,Pudong New District,Shanghai
Zhejiang Chemline International Co., Ltd.
Contact:+86-571-88062298
Address:Hengdian Industry Area, Dongyang, Zhejiang, China
Shanghai Gsyn Chemical Co.,Ltd.
Contact:86-021-67158290
Address:86-021-67158291
Antaeus Bio-technology Co., LTD(expird)
Contact:021-31252569
Address:shanghai pudong
Changsha Yonta Industry Co., Ltd.
Contact:+ 86-731-8535 2228
Address:Rm.1717, North Bldg., No.368, East 2nd Ring Road(2nd Section)
Doi:10.1021/jm00272a031
(1972)Doi:10.1016/S0040-4020(01)92063-0
(1981)Doi:10.1002/hlca.19760590832
(1976)Doi:10.1021/acs.joc.7b02465
(2018)Doi:10.1021/ol048396x
(2004)Doi:10.1248/cpb.29.1548
(1981)
