Diazoethane → Papulacandin B

Participants

Reaction Steps

The ethyl ether of Papulacandin B is prepared as follows: a solution of 1050 mg of Papulacandin B in 30 ml dioxan is allowed to stand at 0° C. for 12 minutes with a solution of diazoethane in ether. After having evaporated off the solvent the residue is chromatographed on a silica gel column (70 g) with chloroform and increasing amounts of methanol (2 to 20%) as eluents. Colorless, amorphous Papulacandin B-monoethyl ether is obtained after precipitation from acetone/ether/hexane. The IR-spectrum (in KBr) shows the following bands: 3500, 2970, 2950, 1710, 1620, 1465, 1380, 1345, 1305, 1265, 1150, 1070, 1035, 1010 cm-1. The UV-spectrum (in ethanol) shows the following maximum values: λmax. (εmax.): 235 (40000), 265 (40000), 294 (shoulder). The 13C-NMR-spectrum shows the presence of an additional ethyl group Papulacandin B-diethylether, in which the 13C-NMR-spectrum shows that two additional ethyl groups are present, is obtained as further product.

Provenance & Evidence