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ChemicalBook CAS DataBase List Paclitaxel
33069-62-4

Paclitaxel synthesis

7synthesis methods
The total synthesis of paclitaxel (Taxol) is described. Double Rubottom oxidation of the bis(silyl enol ether) derived from a tricarbocyclic diketone effectively installed a bridgehead olefin and C-5/C-13 hydroxy groups in a one-step operation. The novel Ag-promoted oxetane formation smoothly constructed the tetracyclic framework of paclitaxel.
Total Synthesis of Paclitaxel
The biosynthesis of paclitaxel involves the condensation of the three isoprenyl diphosphate (IPP) units with dimethylallyl diphosphate (DMAPP). Plants are unique in producing IPP and DMAPP by both the mevalonic pathway (MVA) in the cytosol or via the methylerythritol phosphate (MEP) pathway in the plastids.
Paclitaxel: biosynthesis, production and future prospects
-

Yield:33069-62-4 100%

Reaction Conditions:

with hydrogenchloride;water in ethanol at 0 - 20; for 2.41667 h;

Steps:

28

Example 28: Paclitaxel.; To a solution of 7-O-(triethylsilyl)pacl itaxel (7 mg) in ethanol (2 ml_) at 0 0C was added HCI (2 M, 2 ml_). The reaction was stirred for 2h and 25 minutes from 0 0C to room temperature. Next, EtOAc and aqueous sodium hydrogencarbonate were added at 0 0C. The mixture was extracted with dichloromethane, and the organic layer was dried over sodium sulfate. After filtration of the mixture and evaporation of the solvent, the crude product was purified by silica gel column chromatography to afford paclitaxel in quantitative yield as a white solid. 1H NMR (400 MHz, CDCI3): δ - 8.13 (d, J=8.4Hz, 2H), 7.74 (d, J=8.8Hz, 2H), 7.64-7.58 (m, 1 H), 7.53-7.46 (m, 5H), 7.44-7.34 (m, 5H), 6.98 (d, J=8.8Hz, 1 H), 6.27 (s, 1 H), 6.23 (t, J=8.8Hz, 1 H), 5.79 (dd, J=2.8Hz, J'= 6.4Hz, 1 H), 5.67 (d, J=6.8Hz, 1 H), 4.96 (d, J=8.0Hz, 1 H), 4.79 (d, J=2.4Hz, 1 H), 4.40 (dd, J=AAHz, J'=6.8Hz, 1 H), 4.30 (d, J=8.4Hz, 1 H), 4.20 (d, J=8.4Hz, 1 H), 3.80 (d, J=7.2Hz, 1 H), 3.54 (bs, 1 H), 2.59-2.50 (m, 1 H), 2.38 (s, 3H), 2.36-2.28 (m, 2H), 2.34 (s, 3H), 1.92-1.84 (m, 1 H), 1.80 (s, 3H), 1.68 (s, 3H), 1.25 (bs, 2H), 1.24 (s, 3H), 1.14 (s, 3H); 13C NMR (100 MHz, CDCI3): 203.6, 172.7, 171.3, 170.4, 167.0, 167.0, 142.0, 137.9, 133.7, 133.6, 133.2, 132.0, 130.2, 129.1 , 129.0, 129.0, 128.7, 128.7, 128.4, 127.0, 84.4, 81.2, 79.0, 76.5, 75.6, 74.9, 73.2, 72.2, 58.6, 55.0, 45.6, 43.2, 35.7, 35.6, 26.9, 22.6, 21.8, 20.8, 14.8, 9.5; HRMS (ESI): calcd for [M+Na] (C47H5I NOi4) requires m/z 876.3202, found 876.3191 : [α]D = -50.0 (c=0.1 , CHCI3); melting point: 195-197 0C.

References:

WO2010/62239,2010,A1 Location in patent:Page/Page column 21-22

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